Lab Said the DNA Is “Too Complex” in a Sexual Assault Case — Is the DNA Unusable?

Short answer

No. “Too complex” usually means the lab observed that a DNA sample has too many mixed contributors or DNA overlap, and they are unable to interpret the data. TrueAllele^® Casework can often recover more information from the same lab DNA data. Investigators should not give up on the DNA. The next step is to request the electronic DNA data files and screen the most probative items.

What to do next

1. Confirm which item the lab called too complex.
2. Start with the most probative item first, like rape kit samples or victim clothing.
3. Request the required electronic DNA data files (.fsa or .hid).
4. Submit a Free TrueAllele Screening inquiry.
5. Use the screening result to decide whether a court-ready case report is worth pursuing.

What to send

• Please do not send biological evidence. The screening uses the lab’s autosomal STR electronic DNA data files (.fsa or .hid).

Please submit:

• For the ”too complex” evidence items, the lab’s electronic data (.fsa or .hid)
• For reference profiles (victim/elimination/POI), either allele lists or electronic data files
• Allelic ladder files for any electronic data
• Lab reports or other case documents
• Item ID list (which swabs/items the files belong to)
• A case submission form with case specific information and questions (e.g., compare to POI, interpret the inconclusive mixture, compare items, etc.)

For more information on what to request from the lab, see the Sending Cases for TrueAllele Processing page.

Ready to Submit?

Tell us about your case. We’ll review it and tell you if we can get more information from the DNA data.

Free Screening

We don’t retest physical evidence items. We interpret the electronic DNA data a lab already generated.