Fbi Expert – By Latrishka Thomas
Fbi Expert Links Accuseds
DNA evidence so powerful that it reached into the octillions took centre stage on the latest day of one of Antigua and Barbuda’s most closely watched murder trials, as an FBI forensic expert linked clothing and other items recovered from two separate locations to the men accused of abducting and killing senior Customs official Nigel Christian on July 10, 2020.
A forensic DNA examiner with the Federal Bureau of Investigations, gave evidence virtually and was accepted by the court as an expert in her field. Her testimony — dense with scientific language — was carefully broken down for the jury, offering the clearest picture yet of what investigators found when they tested several items recovered in connection with the case.
The woman began by explaining the science behind her work in terms the average person could follow. DNA, she told the court, is the biological blueprint that makes each of us unique. While human beings share the vast majority of their genetic material — because we are all members of the same species — approximately 1 percent of each person’s DNA differs from everyone else’s.
It is within that small percentage of difference that forensic scientists do their work. The expert explained that her analysis focuses on specific locations within the DNA strand known as Short Tandem Repeats or STRs. Think of these as sections of the genetic code where a small sequence of letters is repeated back-to-back a number of times. The number of repetitions varies from person to person, and that variation is what makes identification possible.
When investigators have a sample from a known person — a cheek swab, for example- she can compare that known profile against DNA extracted from evidence items such as clothing, gloves, or blood. If the profiles do not match, the person is excluded. If they do match, the expert calculates what is called a likelihood ratio — a statistical measure that expresses how much more probable it is that the DNA came from the person of interest compared to a random unknown person from the general population. To put it simply, a likelihood ratio of one million means the DNA is one million times more likely to belong to the named individual than to a stranger picked at random. The numbers that emerged in this trial, in several instances, were far beyond that.
The items were tested against known DNA samples from several individuals connected to the case. Among them were the deceased Nigel Christian, accused Saleim Harrigan, Wayne Thomas, and Lasean Bully, and the witness who told the court he was behind the wheel on the day of the killing, watched the three men force Christian at gunpoint from his own home and into his truck, followed them at a safe distance, later discovered Christian’s body, and ultimately collected the accused after they abandoned Christian’s vehicle.
The witness first disclosed a hat recovered from Cassada Gardens — the area where the victim’s truck was later found abandoned — tested presumptively positive for blood. DNA from the hat came from three individuals, both male and female contributors. Accused Saleim Harrigan was included as a contributor with a likelihood ratio of 7.7 billion [7,700,000,000] — meaning it is that many times more likely that Harrigan’s DNA is on that hat than that of an unknown person. The other persons whose DNA were compared — the driver, Bully, Christian, and Thomas — were all excluded.
A sweatshirt from the same location showed no blood, but DNA testing revealed male and female contributions from three individuals. The cooperating witness known as the driver was included with a likelihood ratio of 33,000. Harrigan was also included, though with a very low probability of 3. The witness was unable to fully exclude Christian from the sweatshirt, though the evidence leaned toward someone else being the contributor — approximately 6 times more likely. All other persons of interest were excluded.
The driver had said in his testimony that he lent this item to Harrigan sometime before the killing.
A shirt from Cassada Gardens, also with no blood detected, yielded male DNA from three contributors. The driver was included with a likelihood ratio of 12 billion [12,000,000,000]. Thomas registered 41, Harrigan 8, Christian 9, and Bully 2. The expert explained that while these numbers represent some statistical support for inclusion, they are relatively low and do not constitute strong evidence of contribution. The driver previously told the court that Bully requested his shirt to use as a mask.
She also explained to the court why investigators specifically test the neckline and armpit areas of clothing, because those are the places where a person’s own DNA is most consistently deposited while wearing a garment.
A glove, however, produced the most striking findings of the day. One glove from Cassada Gardens, tested on the inside, produced DNA from both male and female contributors across three profiles. Harrigan’s likelihood ratio on this item was 42 trillion [42,000,000,000,000] — that many times more likely to be Harrigan than an unknown person. Bully, Christian, Driver, and Thomas were all excluded.
A second glove produced an even more dramatic result. The likelihood ratio for Harrigan on that item was 49 quadrillion [49,000,000,000,000,000].
The witness also mentioned a ski mask type tam which had no DNA matching any of the parties.
Turning to items recovered from Perry Bay — where bags connected to the crime were later found — overalls recovered from the location tested positive for blood on the outside leg. DNA from that area, interpreted as coming from three contributors, placed Harrigan at a likelihood ratio of 210 Septillion [210,000,000,000,000,000,000,000,000].
The driver, Thomas, and Bully could not be excluded, but all had limited likelihood ratios. DNA from inside the overalls suggested two contributors. Harrigan was included at a ratio of 92, and Christian was also included at a low ratio of 2, while Bully, the driver, and Thomas had similarly low figures.
A shirt at Perry Bay produced a likelihood ratio of 3.4 octillion [3,400,000,000,000,000,000,000,000,000] for Thomas, placing him as overwhelmingly the most probable contributor. All others were excluded. A pair of pants from Perry Bay with blood on them yielded DNA results that included Thomas at a likelihood ratio of 11, with Bully at 7, Christian at 2, Harrigan at 3, and the driver at 6 — all low figures the witness described as providing limited support for inclusion.
A shoe from Perry Bay found to have blood on it matched Harrigan’s DNA with a likelihood ratio of 115 million [115,000,000], with all others excluded.
A backpack from the same location, which also tested positive for blood, linked Bully on the outside at a likelihood ratio of 46. Testing of the inner straps and zippers-areas that reveal who handled or wore the bag-produced male DNA from four contributors, with Bully registering a moderate likelihood ratio of 2,400 and Harrigan a ratio of 6. The other persons whose DNA was compared were excluded.
At the end of her examination in chief, the witness explained that environmental factors including sunlight, humidity, heat, and rain can break down DNA over time, which affects the quality and quantity of material available for testing.
Not all 180 items submitted for analysis were appropriate for DNA testing. The expert said she examined just over 50 and each item was not mentioned in open court. She is expected to be cross-examined when the trial resumes on Thursday morning.
Also giving evidence was an Assistant Superintendent of Police, who described receiving information on July 10, 2020, executing search warrants at the home of accused Wayne Thomas, and being present when a ski mask — described in court as a tam with three holes — was recovered at that residence. Under cross-examination by defence attorney Sherfield Bowen, the officer acknowledged that he did not have all officers in his line of sight at all times during the search, that he was inside the premises while others were outside, and that it would be possible for someone to place an item in a yard if an area were left unsecured.
Bowen pressed the officer on several broader issues. He confirmed that the cooperating witness was a member of the Ottos gang, that the witness had two “handlers” within the police service, and that one of them, a senior cop, was present at Perry Bay when the bags were recovered — the tip about those bags having come from the cooperating witness himself. He also confirmed that an officer involved in a car accident with the deceased on the day of his killing is the son-in-law of a public official.
When asked whether he was aware of a plan to kill Nigel Christian communicated by the driver to police in advance, the officer said he was not. He confirmed the head of the Ottos gang had been taken into custody in connection with the case but that the cooperating witness, despite being arrested, was never charged. He also confirmed that Customs officer Cornell Benjamin had been shot months before Christian’s death, and that both men had been part of a team investigating Customs fraud.
The doctor who pronounced Christian dead also took the stand to confirm that.
The trial of Saleim Harrigan, Wayne Thomas, and Lasean Bully centres on the Crown’s allegation that the three men abducted Christian from his McKinnons home on July 10, 2020, and shot him dead on a dirt road in Thibou’s later that afternoon.
At the heart of the Crown’s case is a cooperating witness who testified that he drove the accused that day. He also told the court that Harrigan had named businessman Raymond Yhap as the person who ordered the killing. The witness also testified that he had been in communication with police about a murder plot against Christian before it happened, that Harrigan instructed him to change the licence plates on his rental vehicle, and that he had been asked to buy petrol to burn bags he later directed police to at Perry Bay.
An FBI expert in cellular mapping also gave evidence tracking phone activity of the accused and the cooperating witness to locations consistent with the movements described on the day of the murder, appearing to corroborate the driver’s account geographically.
A digital forensics officer retrieved surveillance footage from several locations including the Chinese Embassy on Marble Hill Road and a nearby business, which the Crown contends shows Christian’s truck being followed by the driver in a silver car. Footage from a neighbour’s camera also captured what appeared to be a vehicle passing Christian’s road and returning within minutes — a detail consistent with the driver’s account. That officer’s credibility was challenged under cross-examination, with Bowen suggesting he had tampered with evidence in the past and was transferred but the witness denied this.
Crime scene photographs shown to the jury depicted Christian lying on the dirt road with gunshot wounds to his face, spent shell casings nearby, and his truck found abandoned in bushes at Cassada Gardens. Items recovered from connected locations included a black hoodie, gloves, a dark tam with holes cut into it, and a white envelope containing a LIAT ticket stub bearing the name N. Christian.
Family members of the deceased gave evidence on Tuesday. A sister confirmed she identified the body and described Christian as a quiet, private man dedicated to his work and family. A brother testified that when he arrived at Christian’s home after the killing, the CCTV recorder was gone and the locks for the kitchen door had been forced. He confirmed that following the death of another Customs officer in 2019, Christian had told him he needed to be vigilant because tensions at work were running dangerously high.
The Crown is led by Director of Public Prosecutions Clement Joseph and Crown Counsel Curtis Cornelius. Harrigan is represented by Wendel Alexander, Thomas by Sherfield Bowen, and Bully by Michael Archibald.
The trial continues before Justice Rajiv Persaud and is expected to last approximately six weeks.