Forensic Biology

OVERVIEW
A biological substance, such as, blood, semen, saliva, or tissue that leaves the human body and is left at the scene of a crime, may provide valuable information as to who was present at a scene and what events might have occurred. The value of this evidence can be greatly diminished if not properly collected, packaged, and preserved. In addition, due to the sensitivity of the DNA technology used by the Forensic Biology discipline, if proper precautions are not taken while collecting evidentiary samples, there is an increased likelihood of introducing contamination from a foreign DNA source unrelated to the crime. It is also possible to transfer unrelated sources of DNA between crime scene samples if the evidence is not packaged correctly.
 
PROCESSING OF EVIDENCE BY THE FORENSIC BIOLOGY SECTION
The initial examination performed by the Forensic Biology discipline is screening the evidence to identify the possible presence of a biological substance (i.e., blood or semen). Probative biological evidence can then be analyzed using a DNA technology specifically designed to test minute amounts of biological material at 24 different areas of the DNA (21 STR markers, 1 Y-STR marker and 2 gender markers). The DNA profile obtained from the “questioned” evidence is compared to the DNA profile from evidentiary known samples (victim, suspect, or elimination buccal samples) to determine if an individual is included or excluded as a possible source of the biological substance. If no suspect has been identified, the foreign DNA profile may be searched against the DNA profiles in the DNA database, CODIS, which is comprised mainly of DNA profiles from convicted offenders and individuals arrested for specific crimes (as per AS 44.41.035), to aid law enforcement in identifying a possible perpetrator.

COMMUNICATIONS FROM THE BIOLOGY DISCIPLINE
March 2018 Memorandum List of Private Accredited Laboratories
February 2018 Letter Regarding SART Exam Authorization Timeframe
November 2017 Quick Reference Guide for DNA Database Collection
June 2015 Memorandum Regarding Amended Population Frequency Database
December 2013 Complex Mixture Memorandum
January 2013 Letter Regarding Disposition of DNA Extracts

 
What can you tell about me from my genetic profile?
STR DNA analysis can identify the gender of an individual. Other STR locations used for forensic purposes are non-coding regions and are not known to influence any individual traits. For example, the STR genetic profile generated cannot tell you if a person has blue eyes or brown, black hair or red, information about height and weight, etc.
 
Why does it take so long to get DNA results?
DNA analysis involves four main laboratory steps: extraction, quantification, amplification and genotyping. Samples are often processed in batches and therefore, completing the four step laboratory process for a batch of samples can take a couple of weeks, once analysis is begun. Once a genetic profile is obtained, the data must be interpreted and a report written. All of the analysts notes, interpretations and the report must then be reviewed by a second qualified analyst. Each of these steps is detail-intensive and time consuming and may take up to several hours for a single sample. In addition, due to a backlog of cases, it may be a few months before DNA analysis begins on a case.
 
I've often heard DNA testing referred to as DNA "fingerprinting". Is DNA testing replacing fingerprints?
No. There are several reasons why DNA testing should not be thought of as a replacement for fingerprints. The term "DNA fingerprint" is somewhat misleading and genetic profile is a more appropriate term for the data generated. Identifying and developing a fingerprint for comparison is relatively inexpensive compared to processing a sample to obtain a DNA profile. Additionally, DNA testing has its limitations – for example, it cannot distinguish between DNA from identical twins. Fingerprints are needed to distinguish between such individuals.
 

Capabilities and Services
The primary function of the Forensic Biology discipline is the identification of biological material and the use of DNA analysis to determine whether the biological material could have originated from a specific individual.
 
The Forensic Biology discipline provides the biological screening and DNA analysis of forensic casework, to include criminal paternity/maternity cases and missing person investigations. Scientific laboratory reports are issued to the investigating agencies.

The laboratory also performs DNA analysis of offender/arrestee samples for entry in the Combined DNA Index System (CODIS). CODIS hit letters are issued to notify law enforcement when there is a DNA match between samples in the DNA database. CODIS hits are investigative leads, typically identifying a potential source of biological material from crime scene evidence.

The laboratory routinely performs the analysis on the following types of samples: The laboratory does not routinely perform analysis on the following:
  • vomit
  • urine
  • fecal matter
  • fired casings/bullets
  • condom wrappers
  • unopened beverage containers
  • cigarette packages or unsmoked cigarettes
  • charred/burnt material
  • controlled substance cases
  • items previously examined/processed in another laboratory; to include dusting for fingerprints
  • items taken directly from a suspect in a possession case
The laboratory generally will not perform DNA analysis in cases where potential suspects have already been identified via latent print identifications.

The laboratory also does not perform STD testing. The public health laboratory performs testing to confirm the presence of some viruses, but they are not able to perform DNA analysis to identify particular strains of a virus. Agencies should contact the health lab directly for additional information.

Mitochondrial testing must also be sent to a private lab for testing. Mitochondrial DNA testing for missing persons cases may be submitted to the University of North Texas Health Science Center (UNT).


Click here for a list of other accredited, private laboratories for forensic DNA analysis. Links to private laboratory websites can be found under the Links tab further down this page.

RUSH analysis
Cases are prioritized for analysis. Crimes against a person are given priority over property crimes, with the most severe offenses being placed ahead of other cases. Requests for RUSH analysis shall be made to the Forensic Biology supervisor. Requests will be considered in cases with pending court dates/deadlines or where there is an immediate threat to public safety. A case will not be elevated to RUSH priority if the laboratory has not received the required known reference samples.

Communication with agencies
Often, the laboratory will require additional information or evidence to complete the analysis. It is imperative that requests are responded to in a timely manner to prevent unnecessary delays in evidence processing. Failure to response within 30 days may results in suspension of the request for analysis.

Item Selection Guidelines and Policies
The following guidelines, utilized by laboratory personnel in sample selection, have proven effective, but may vary slightly on a case-by-case basis. Items are selected based on their probative value (i.e. the degree to which the results can either prove or disprove the alleged events). Once probative results are obtained, additional analyses are unlikely to be performed.

Sexual Assault - the number of samples analyzed will generally correlate with the number of possible assailants and/or consent partners who may be DNA contributors; typically, one questioned sample per possible foreign contributor. Known samples from the victim(s) and suspect(s), if known, are required. Known samples from consent partners are highly recommended.

***In sexual assault cases with unknown allegations (i.e. no recollection of events), analysis will be limited to body swabs for semen and breast swabs (bite marks, etc.) if indicated by forensic history. Underwear will only be processed if they are the pair known to be worn immediately post-event and SART kit was collected beyond 48 hours.

Non-sexual Assault - the number of samples analyzed will generally correlate with the number of possible DNA contributors; typically, one questioned sample per possible foreign contributor. Known samples from the victim(s) and suspect(s), if known, are required.

Homicide - the number of samples analyzed will vary based on the number of potential DNA contributors and the number of items with potential probative value.

Criminal parentage cases - Reference samples are required from the mother, alleged father and child (or products of conception). Exceptions require consultation with the DNA Supervisor.

Property Crime Cases - Typically only one or two questioned samples will be analyzed per case. Selection of samples is at the discretion of the laboratory and based on the likelihood of obtaining an interpretable profile. Bloodstains and saliva samples (e.g. cigarette butts, mouth area of bottles and cans) are most likely to yield DNA profiles suitable for comparison.

*** Contact DNA samples will be limited to items brought to and/or left at the scene by the suspect. Items inherent to a scene that were only briefly touched or handled by a perpetrator do not typically yield interpretable foreign DNA profiles and will not be processed by the laboratory.

***Only steering wheel and gear shift contact/touch DNA swabs will be processed from vehicles, as these have proven the most likely to yield interpretable DNA profiles. Reference buccal swabs from the owner/primary driver of the vehicle must accompany the submission of vehicle swabs or analysis will not occur.

***Owing to the low success rates for contact DNA swabs from firearms, the lab requires that reference buccal swabs accompany the submission of firearms or swabs from firearms for contact DNA analysis. Reference buccal swabs from known suspects AND registered owners are required for contact swabs from stolen firearms. Reference buccal swabs from known suspects are also required in Misconduct Involving Weapons and Felon in Possession cases. Analysis will not occur without the required reference samples.

***DNA on file is NOT an acceptable reference sample.

 
Biological Material
Body fluids such as blood, seminal fluid or saliva, or a biological substance such as hair and tissue (muscle, fetal material, etc.)
 
Buccal Swab 
A swabbing of the inside of a person's cheek to collect cells for the purpose of obtaining a reference DNA profile.

Contact or Touch DNA Evidence
Evidence resulting from casual contact by an individual with a surface or material. This would include primarily objects touched by an individual’s hand(s), such as gun grips, triggers, knife handles, steering wheels, etc.

Deoxyribonucleic Acid (DNA)
The genetic material found in various body tissues (muscle, fetal tissue, skin, etc.) and body fluids (semen, vaginal fluid, blood, saliva, etc.). Because an individual’s DNA is the same from cell-to-cell within the body and is different from individual-to-individual, DNA can be used to determine whether a biological substance may have been deposited by a specific individual.
 
DNA Database Collection Kit (offender kit, CODIS kit)
A kit used for the collection and preservation of statutorily mandated DNA samples (from convicted offender and arrestees) for entry in the DNA database.
 
DNA Profile
The combined results that are obtained when testing DNA at several locations on various chromosomes; from the nucleus of the cell. The DNA comprising an STR profile is inherited from both biological parents.
 
Mitochondrial DNA (mtDNA)
Mitochondria are organelles in the cell that contain their own DNA. Mitochondrial DNA (mtDNA) is different from nuclear DNA. Each mitochondrion contains a few hundred to several thousand copies of mtDNA. Mitochondrial DNA is maternally inherited, meaning maternally related close relatives will have the same mtDNA profile. Therefore, mtDNA is less discriminating than nuclear DNA STR testing. However, mtDNA testing is more likely to be successful when samples are highly degraded due to age or environmental insults.
 
Semen
A biological substance secreted by males that consists of a combination of seminal fluid and spermatozoa.
 
Seminal Fluid
A biological fluid produced by males for the transport of spermatozoa. May be absent of spermatozoa in vasectomized males or males with certain medical conditions.
 
Sexual Assault Kit (SAK)
A set of items used by medical personnel for the preservation of physical evidence collected from a person, living or deceased, following an allegation or suspicion of sexual assault.
 
Spermatozoa
The male cell involved in reproduction; carries one-half of the genetic information for a new individual.

STR DNA Analysis (Nuclear DNA)
STR DNA analysis is the most widely used method in crime laboratories and is the only method currently utilized at the AK State Crime Lab. STR (Short Tandem Repeat) testing targets and amplifies specific locations in the DNA molecule. This testing can be performed to identify not only the gender of the source of the biological material but also generate a genetic profile which enables us to distinguish between two individuals with a considerable degree of confidence.

 
Wearer DNA
DNA recovered from an article of clothing in an effort to identify the wearer of the garment.
 
Y-Chromosome DNA (Y-STR DNA)
Male specific DNA found in the nucleus of most cells of the body. Y-STR analysis is used to amplify locations on the Y chromosome and Y-STR data can only be obtained from male individuals. This type of DNA is inherited paternally. This type of testing may be useful when samples are mixtures of male and female DNA or when there is very little DNA from a male contributor. Y-STR testing has its limitations since close male relatives will have the same Y-STR profile.

 

Forensic Biology procedure manuals are located in a tab under the Quality Assurance section of the webpage. They can be accessed by clicking here.
Biological fluids and body fluid stains are valuable evidence which can be used to either associate a victim or suspect with a crime/crime scene or eliminate them from consideration. The most frequently encountered biological fluids are blood, seminal fluid, and saliva.

Safety Precautions
It is imperative when collecting or packaging biological evidence for submission to the laboratory that clean latex gloves be worn and changed often. Depending on the crime scene, shoe covers, gowns, masks, head covers, and safety glasses may also be appropriate. Body fluids, wet or dry, have been shown to carry disease. Dry stains may flake when disturbed or collected, sending minute particles airborne. These may be absorbed through mucus membranes (eyes, nose, mouth, etc.), open cuts, or chapped skin. Therefore, all biological materials and fluids must be handled with universal precautions. Wearing the appropriate protective clothing also helps minimize contamination of the evidence sample with your DNA.

General Collection Guidelines
All biological evidence should be air-dried prior to submission to the laboratory. Refrigerating the evidence will retard bacterial growth on wet material. However it will not stop the growth which can then lead to degradation of the biological material. The sooner the biological evidence is dried, the more likely useful information can be obtained from the evidence through DNA analysis.

Biological evidence should be packaged in envelopes or paper bags; NEVER in plastic bags.

During the collection, air-drying, or packaging of any body fluid stains, caution should be used to ensure that a stained area from an item of evidence does not come in contact with another stained or unstained area. This applies to outer surfaces and inner surfaces. For example, a shirt should not be folded or rolled so that a stain on the front contaminates any stained or unstained area on the back or inside of the shirt. A barrier, such as paper or cardboard should be placed on the inside of the shirt, as well as under and over the garment to prevent stained areas from coming in contact with each other.

When air drying articles stained with body fluids, place them on or over a piece of clean paper. Any debris which falls from the material onto the paper during the drying process will be collected when the paper is folded with the article prior to packaging, labeling and sealing.

Body fluid evidence can be contaminated by the crime scene officer's own body fluids. The perspiration on the officer’s hands may contaminate the cotton swabs used to collect the body fluids, or talking while collecting samples may spread the officer’s saliva on the evidence. To prevent such contamination protective clothing (i.e., latex gloves, gowns, masks, and head covers) should be worn while collecting the evidence. To avoid possible sample-to-sample contamination, change latex gloves (and other applicable protective wear) as necessary when collecting evidence.

When practicable, it is best to submit the entire item of evidence to the laboratory for evaluation. If an item has been swabbed by the agency, the laboratory will not analyze the item the swab was taken from for DNA analysis. Evidence (once packaged) should be submitted to the laboratory as soon as possible. Otherwise, the items should be stored in an appropriate secured storage location until submission to the laboratory is possible. To minimize degradation of DNA, evidence should not be stored in extreme humidity or at elevated temperatures. Dry, cool storage locations are best.

Body Fluids on Non-Porous Surfaces (i.e., bottles, cans, window, knife, firearm, body, etc.)

  1. Double-Swab Method: (For samples taken from non-porous objects like bottles, cans, windows, knives, firearms, etc.) A sterile swab is moistened with sterile/distilled water (WET) and the area of interest is swabbed. Using the second sterile swab (DRY) immediately re-swab the area. Let the swabs dry before packaging. Two swabs only should be collected per area of interest.
  2. Single-Swab Method: (For samples taken from areas of the body such as external genitalia, finger/hand swabs, neck swabs due to possible strangulation, etc.) Moisten one sterile swab with sterile/distilled water and swab the area of interest. Let the swab dry before packaging. One moist swab only should be collected per area of interest.
  • Note: Double-tipped swabs and Q-tips should not be used.
  • Note: Avoid scraping crusts due to risk of airborne flakes.

Swabs from an item of evidence, such as the mouth of a bottle or an area of the grip of a firearm of no value for latent print examination, can be submitted for DNA analysis while the actual item of evidence can be submitted for examination by the Latent Print or Firearms disciplines

The Forensic Biology Section no longer analyzes control swabs, therefore there is no need to collect or submit a control swab to the laboratory.

Body Fluids on Porous Surfaces (i.e., clothing, bedding, carpet, untreated wood, etc.)

Submit the air-dried item of evidence if possible. For large items (large carpets, upholstered furniture, etc.) it may be necessary to cut out the stained areas or swab the stained area with a sterile swab moistened with one to two drops of water. Saturate one swab with the stain before absorbing onto the next swab. Allow the swab(s) to air dry or place the swab(s) in a new labeled swab box for drying. It is not necessary to collect more than 2 saturated swabs for submission to the laboratory.
 
If cuttings/swabbings are taken from different areas on an item, package the cuttings/swabbing from each area separately. The packages from separate cuttings/swabbings of a single item may be sealed individually and then combined into a larger package.
  • Note: Double-tipped swabs and Q-tips should not be used.
  • Note: Avoid scraping crusts due to risk of airborne flakes.
The Forensic Biology Section no longer analyzes control swabs, therefore there is no need to collect or submit a control swab to the laboratory.

Sexual Assault Evidence Collection Kit (SART kit or SAK)

A kit used for the recovery of physical evidence from the body of the potential victim or suspect of an alleged sexual assault. A specialized kit exists for pediatric victims. The kit contains supplies to recover foreign secretions and trace evidence (i.e., hairs) from the body. In addition, the kit contains supplies for the collection of a known sample from the individual for comparison with the foreign secretions and hairs. Kits are supplied by the laboratory and may be requested via an e-mail to  DPS.supply.orders@alaska.gov.
 
The laboratory may be able to recover foreign DNA from a female victim up to 7 days after the event. Personnel are urged to follow the instructions supplied with the kit and to complete all portions of the kit paperwork. The forensic history in particular, is essential to laboratory scientists during their analysis.

***Laboratory supplied kits should be used even when collecting only penile swabs or hand swabs and a reference sample from an individual. These samples should not be submitted as separate items when they are collected as part of a sexual assault investigation.

DO NOT USE SART KITS FOR ANY PURPOSE OTHER THAN THE COLLECTION OF SEXUAL ASSAULT EVIDENCE.

Condoms

Used condoms should be air dried and submitted to the lab for processing. When the condom contains a volume of liquid, place two (or more if needed) sterile swabs in the condom to absorb the liquid. DO NOT pack the condom with gauze or paper towels. Allow the outer surface of the condom to air dry and package in a sealed envelope for submission to the lab. The lab will not routinely analyze unused condoms.

Contact DNA Evidence

Submit the item of evidence (preferred) or take a swabbing of the evidence with a single sterile cotton swab that has been slightly moistened with one (1) to two (2) drops of water. Allow the swab to air dry or place the swab in a new labeled swab box for drying. A single swab is recommended for collection to concentrate the foreign DNA that may be present and to increase the likelihood of collecting sufficient biological material to obtain a DNA profile.
  • Note: Double-tipped swabs and Q-tips should not be used.
When an item requires both latent print and DNA analysis, biological screening is typically done prior to latent print examinations. Typically, smoother items (blades, slides of guns, etc.) are better for latent print recovery and textured surfaces (grips, handles, etc.) are better for contact DNA recovery. Some items are better suited for one examination or the other and will not have both types of processing performed, even when requested. The following items will not routinely have both contact DNA and latent exams conducted:
  • Casings/bullets – only latent print examination will occur
  • Condom wrapper – only latent print examination will occur
  • Unopened beverage containers – only latent print examination will occur
  • Beverage containers likely drank directly from – both exams are possible. If probative findings are obtained from either latent prints or DNA, the other analysis will generally not be performed
  • Cigarette packages – only latent print examination will occur
  • Cigarette butts (smoked) – only DNA analysis will occur
  • Unsmoked cigarettes – neither examination will occur

Known/Reference Buccal Swabs

Buccal swabs are collected by taking two (2) sterile cotton swabs and swabbing the inner cheeks of the mouth. The swabs should be rotated during the collection process to maximize collection of cells. Let swabs dry then place both swabs together into one labeled envelope. It is not necessary to collect separate samples from the left and right inner cheeks. This is considered all one sample.
Reference samples should be collected from all persons suspected of involvement in an investigation, who may be contributors of biological evidence. These samples are part of the SART kit, but must be collected separately for persons on whom a SART kit has not been collected. The laboratory will provide swabs specifically for collecting known samples that are not part of a SART kit collection. Requests for swabs should be sent to
DPS.supply.orders@alaska.gov.
 
“DNA on file” with the DNA database (CODIS) is NOT an acceptable substitute for an evidentiary known sample with a proper chain of custody. Known/reference samples should be collected for each separate criminal investigation that an individual is associated with. These samples should be submitted along with other evidentiary material to ensure that laboratory testing is not suspended pending receipt of known samples.

DNA Database Collection Kit

These kits are exclusively for use in collecting the statutorily mandated samples from arrestees and convicted offenders as per AS44.41.035. The kit contains instructions for the proper collection of the samples (buccal swabs and thumb prints) and completion of the information card. Kits can be obtained by e-mailing DPS.supply.orders@alaska.gov. DO NOT USE DATABASE COLLECTION KITS FOR ANY PURPOSE OTHER THAN THE COLLECTION OF CONVICTED OFFENDER AND ARRESTEE SAMPLES.

Products of Conception (for Criminal Parentage Investigations)

Tissue collected from an aborted fetus that is 10 to 12 weeks old may contain identifiable body characteristics (i.e., hands and feet) that can easily be isolated by the DNA analyst for testing. If the fetus is less than 10 weeks old, the body characteristics may not be easily identified by the examiner.
 
When possible, request the medical doctor to isolate a portion of the fetal tissue from the maternal tissue and place the fetal tissue into a hard plastic container (i.e., specimen cup). Alternatively, the entire aborted fetal material may be submitted.

 
  • Note: The fetal tissue/material should not be stored in a saline solution or any other type preservative.
Submit the container to the laboratory the same day. If it is not possible for the aborted fetal tissue/material to be submitted to the laboratory the same day, place the container into a refrigerator and submit to the laboratory the next day. When submission cannot be achieved within 24 hours, the sample should be frozen. Within a short period of time fetal tissue/material stored in plastic, even if refrigerated will promote bacterial growth, which can destroy biological material and potentially preclude the examiner from obtaining DNA results. 
 
* Commissioner memo regarding update to SAK Collection Timeframe - February 2018

***Laboratory supplied kits should be used even when collecting only penile swabs or hand swabs and a reference sample from an individual. These samples should not be submitted as separate items when they are collected as part of a sexual assault investigation.

DO NOT USE SART KITS FOR ANY PURPOSE OTHER THAN THE COLLECTION OF SEXUAL ASSAULT EVIDENCE.


To order kits, e-mail DPS Supply at DPS.supply.orders@alaska.gov.

Sexual Assault Kit paperwork
Fillable SAK form for adult kits
Fillable Pediatric Kit form
Complete adult kit paperwork - August 2018 version
Pediatric kit paperwork - August 2013 version

Additional Resources
National Best Practices for Sexual Assault Kits
A National Protocol for Sexual Abuse Medical Forensic Examinations Pediatric

2018-SAKI-backlog-Executive-Summary printable version
AS 44.41.035 authorizes the collection of DNA samples from persons arrested or convicted of a Crime Against A Person or a felony under AS 11 or AS 28.35. The DNA profiles from these samples are maintained by the laboratory in CODIS (the Combined DNA Index System). The CODIS database also contains DNA profiles obtained from crime scene samples, unidentified human remains, missing persons, and relatives of missing persons. The main purpose of the database is to generate investigative leads in cases where biological evidence was recovered from a crime scene.

Law enforcement and corrections officers across the state are to collect the DNA samples as buccal swabs (cheek swabs), and submit them to the laboratory for analysis. Kits designed specifically for this purpose are provided by the laboratory and can be obtained by e-mailing
DPS.supply.orders@alaska.gov.

Click here for guidance on determining who is required to give a sample.

Click here for an overview on the CODIS System and CODIS Sample eligibility.

 
CODIS Metrics as of January 2018
  Alaska National Database
Investigations Aided 727 390,584
Crime Scene Profiles in database 1857 830,184
Arrestees in database 33,121 2,984,137
Convicted Offenders in database 24,368 13,094,164

Click here to visit the FBI Laboratory's CODIS webpage.
 
The Alaska crime laboratory is now online with Y-STR analysis. Y-STR analysis will not be performed retroactively on cases the laboratory has already completed, with the exception of cases involving the Sexual Assault of a Minor.

For all other cases, if Y-STR analysis is needed on a case the lab reported prior to March 2018, testing will need to be completed at a private lab. The law enforcement agency is responsible for selecting a lab and arranging for payment. If the evidence is currently at the Alaska crime lab, we will send the items directly to the private lab on the agency's behalf.

Click here for a list of accredited, private laboratories. Links to private laboratory websites can be found under the Links tab further down this page.

Click here for a brief tutorial on Y-STR analysis.

 
Rapid DNA, or Rapid DNA analysis, is a term used to describe the fully automated (hands free) process of developing a DNA profile from a reference sample buccal (cheek) swab without human intervention. The laboratory does not currently offer this service and has no immediate plans to implement it.

Click here to visit the FBI Laboratory's webpage on Rapid DNA Analysis

Position Statements on Rapid DNA
ASCLD-Position-Statement-RAPID-DNA
NDAA-Statement-on-Use-of-Rapid-DNA-Technology-2018
SWGDAM-Position-Statement-Rapid-DNA
General DNA Related Information
Websites of Professional Organizations


Commercial Manufacturers of Laboratory Chemistries


Websites of Private Accredited DNA Laboratories

(not an all inclusive list)


Publications

B. Budowle, T. Moretti, A. Baumstark, D. Defenbaugh, K. Keys, Population Data on the Thirteen CODIS Core Short Tandem Repeat Loci in African Americans, U.S. Caucasians, Hispanics, Bahamians, Jamaicans, Trinidadians. Journal of Forensic Science 1999;44(6): 1277-1286.

B. Budowle, A. Chidambaram, L. Strickland, C. Beheim, G. Taft, R. Chakraborty, Population studies on three Native Alaska population groups using STR loci. Forensic Science International 129 (2002) 51-57.

Moretti, T. et.al, Population data on the expanded CODIS core STR loci for eleven populations of significance for forensic DNA analysis in the United States (2016) Forensic Science International: Genetics 25: 175 - 181.


 Expanded Loci Genotyping and Statistical Evaluation of Three Alaskan Native Populations