New publication - The reliability and reporting of DNA match strength for uncertain genotype evidence.

Why Low-Level DNA Can Hinder Cases — and How Investigators Can Still Get Leads

Short answer

When a lack of DNA information hinders a case, investigators usually feel the same frustration: the item mattered, the testing happened, but the initial interpretation result did not help the case.

That does not always mean the evidence is worthless. It often means that there is informative DNA that goes unreported.

Why Low-Level DNA Can Hinder Cases

Low-level DNA often comes from the very items investigators care about most: handled objects, touched surfaces, worn clothing, mixed samples, and damaged evidence.

Those items are more likely to produce limited DNA data. The problem is not always that the item had no value. The problem is that the interpretation did not produce an informative result.

Why Can’t My Lab Find Information from Low-Level DNA?

Because limited DNA is more vulnerable to information loss for threshold-based interpretation methods.

In our recent peer-reviewed Heliyon paper, we demonstrate that thresholds and reporting cutoffs can suppress useful DNA information, especially in evidence with multiple contributors or little DNA. That means an item can contain case-relevant information without producing a strong or easily reportable first result.

What That Means for the Case

The published study in Heliyon makes clear that limited evidence does not always have no DNA information. The evidence is limited by interpretation and reporting protocols that reduce the information before it reaches the investigator.

For the case, that changes the question. The issue is not just whether DNA was tested. The issue is whether the initial result produced usable information.

When Re-interpreting Same DNA Data May Still Help

If the item is important, the next question is whether TrueAllele re-interpretation of the same data can help.

That is especially true when:

  • the initial result was reported as insufficient or limited
  • the case remains open
  • the evidence still matters for reference identification, exclusion, or scene reconstruction

Featured Case Example

The Noriega case is a good example of this scenario. The crime lab developed low-level mixture data from the burned victim’s body swabs but could not draw conclusions because of data complexity. On the same data, TrueAllele later connected Jose Noriega to the victim’s body, and the evidence aided in a conviction.

When to Request a Free TrueAllele Screening

A free TrueAllele screening makes sense when:

  • the item matters
  • the current DNA result is limited or uninformative
  • the evidence is mixed, low-level, touched, or degraded
  • you need to know whether the same data may still produce usable information

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.