The use of insects as a tool in investigations is a popular topic as any new evidence allows for a more accurate retelling of a crime, leading investigators to the criminal or to identifying the victim. Forensic entomologists are exploring them as vectors of human DNA, as the ability to collect and extract DNA from various sources is essential for investigations since DNA has increasingly become the standard in forensic science. Despite their potential in forensic science, previous work has yet to compare the effectiveness of certain bugs in their ability to be used as DNA sources. The scope of this review was limited to hematophagous (blood-eating) and necrophagous (carrion-eating) insects. Papers from only the last five years were reviewed, with a preference for more recent research articles. Databases that were consulted included PubMed, Forensic Science International, and the International Journal of Legal Medicine with searches including the words “insect”, “forensic”, and “Human DNA”. When comparing the insects, human DNA lasts the longest post-feeding inside bed bugs allowing for more accurate DNA profiles. Mosquitoes and flies showed promise as DNA vectors.