In some criminal cases, the use of classical sources of human genetic material is difficult or even impossible. One solution may be the use of insects, especially blowfly larvae which feed on corpses. A recent review of case reports and experimental studies available in biomedical databases has shown that insects can be a valuable source of human mitochondrial and genomic deoxyribonucleic acid (DNA), allowing for an effective analysis of hypervariable region (HVR) sequences and short tandem repeat (STR) profiles, respectively. The optimal source of human DNA is the crop (a part of the gut) of active third-instar blowfly larvae. Pupae and insect faeces can be also used in forensic genetic practice instead of the contents of the alimentary tract.