Hair DNA Testing Used in Criminal Investigation

14 Aug 2017

Thanks to hair DNA testing, Jason Maestrello, 34, accused and charged with two counts of murder in 2005 in Cornwall, Canada has had evidence of the murders linked back to him. Maestrello and his murder accomplices are said to have taken a boat to dump some clothes, towels, and guns into St. Lawrence River. DNA tests on hairs found on the towel in the river waters proved to belong to Maestrello.

The hair sample has enabled a DNA profile to be drawn up and compared to the DNA of Maestrello. The comparison showed a match and thus, the hair sample could not be excluded as belonging to Maestrello. DNA hair testing followed. The towel was found to have 4 hairs and two of these were matched back to Maestrello thanks to DNA testing with hair. The investigation required Jason, his partner Michael Boyle, two alleged drug traffickers Andy Paul and Roger Belair, Belair’s X wife and the benedicts to give blood DNA samples so as to be able to extract a DNA profile from this sample and compare it to the DNA in the hair. The 2005 murders in which Jason is implicated involved the shooting of his two cousins, Peter and Jade Benedict, 34 and 27 years of age respectively. The killings were a result of a large debt that the two had to pay Maestrello, a drug dealer. Allegedly, the two owed him some $160,000 for a sale of marijuana.

Further investigation yielded two cigarette ends which however, did not provide DNA profiles that could accurately be linked to any of the known profiles.

Hair DNA Testing: 2 Types of DNA

If hairs used have the hair follicle or root, than analysts can extract another type of DNA which is known as nuclear DNA; this is the type of DNA most often found and used in forensic investigations as it gives a much more specific and accurate profile. This type of DNA is also used in paternity tests, relationships tests and twin tests; in such cases, it is possible to carry out a hair DNA test so as long as the hair has the root.

Hair DNA testing in the case involving Maestrello cannot be entirely conclusive and the probability of it belonging to Maestrello is just 1 in 556 (based on the limited number of Caucasian DNA profile in the FBI database). The DNA tested for in the case was based upon the samples of hair found on the towel. The hairs in this case were likely to be naturally shed hairs which in themselves do not contain the ideal DNA for DNA testing. Hairs contain what is known as MtDNA (Mitochondrial DNA), a type of DNA which is passed solely down the maternal line; this means that along with Maestrello, other female relatives may also be implicated in the crime.

Nowadays, highly advanced forensic testing methods allow for DNA profiles to be extracted from the most difficult and even degraded samples.

Hair DNA testing involving mitochondrial DNA, as in the above case, required further laboratory analysis to check that the MtDNA has not been contaminated by other DNA.