Questions answered in this file

Can DNA survive for decades in storage?

Sometimes. Dried biological material stored in stable, dry conditions can yield DNA many years later, though results vary widely.

Why is plastic packaging bad for biological evidence?

Plastic can trap moisture, encouraging mould and bacteria that degrade DNA, which is why breathable paper packaging is generally recommended.

Where else might samples from an old case be kept?

Medical examiners, crime laboratories, hospitals and court clerks may hold samples, extracts, slides or exhibits under their own retention rules.

Does degraded DNA make testing impossible?

Not always. Degradation can reduce DNA quantity and quality, producing partial results, but only a laboratory assessment can confirm what is possible.

What can a family ask about stored evidence?

Ask in writing whether biological evidence was retained, how it was stored, whether it was tested and whether retesting has been considered.