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.
Why are we being required to submit known reference samples from victims (like the owner of a stolen vehicle) or other innocent persons (like the consent partner of a sexual assault victim) when we only need to identify the suspect’s DNA?
There are several rules that must be followed for the laboratory to be a participant in the national DNA database (CODIS). One of those rules is that we are only permitted to enter DNA profiles from items of evidence when the profile is likely from the perpetrator of the crime. We must make every effort to ensure that we are not entering DNA profiles from victims or other innocent persons whose DNA may be on an item. Since there is a reasonable expectation that the DNA from the owners/permitted drivers of the vehicle would be found on the steering wheel or gear shift, we need to rule those persons out as the source of the DNA profile. If we were to get DNA from a steering wheel and don’t have the victim’s known, there is the potential to inadvertently upload the victim’s DNA to the database. Providing these victim known samples ensures that the privacy rights of the victim are maintained.
This is why we also require reference samples from the owners of stolen weapons and why we request them for consent partners in sexual assault investigations.
What is the victim refuses to give me a known sample or the vehicle was stolen weeks or months ago and just recently recovered?
These are circumstances in which the laboratory will make an exception to the policy. The Request for Laboratory Services (RLS) form was specifically designed to make it easy to provide this information to the laboratory.
Any time you request DNA analysis, you will be required to fill out a supplemental page. The drop down menus give you the option to select “Victim uncooperative” if you request a sample and the victim refuses. In that situation, you should make sure the victim understands that there sample can only be used for elimination purposes in this case and is for the sole purpose of making sure their DNA IS NOT entered into the database.
This sample drop down menu gives the option of “Victim not likely to be source of DNA”. This would be applicable in the scenario where the vehicle was recovered weeks or months after being stolen. You can add that additional information in the box for additional information at the bottom of the supplemental page.
Again, the CODIS rules are designed to protect the privacy of victims and therefore, it is essential that victim samples are always requested and that the RLS form is completed accurately.
How do I collect, package, store and ship my reference samples?
These questions are addressed in a separate document with detailed instructions as well as a script to assist you in conveying this information while interacting with persons from whom you are requesting a known reference sample. If you are unable to obtain the known reference sample voluntarily, review the facts of the case and consider obtaining a search warrant. Click here to open the document. Voluntarily collected reference samples must be accompanied by the laboratory consent form, found here.
I see that there is DNA on file for the person(s) involved in my case. Why can't the lab use this sample for comparison in my case?
DNA on file means that the individual has provided a convicted offender or arrestee sample in accordance with AS44.41.035. These samples are processed by the laboratory and entered into the DNA database (CODIS). These samples are not an acceptable reference sample for a criminal investigation because they are not evidentiary in nature. When they are collected and submitted to the lab they do not have a chain of custody and as such cannot be used in court proceedings.
The purpose of these database samples is to provide investigative leads in unknown suspect cases. They are not intended to be a substitute for an evidentiary reference sample. When the lab reports a CODIS hit in a case, the investigating agency should collect an evidentiary known to submit to the laboratory for confirmation. Only then, will the laboratory issue a scientific report that identifies the suspect and is suitable for admission in court proceedings.
Whenever possible, providing evidentiary known reference samples to the lab up front [with a Request for Laboratory Services form] means that the laboratory can complete analysis on the case in a more timely and efficient manner.