The lead investigator in the murder trial of three men accused of killing senior Customs officer Nigel Christian acknowledged on Friday that she had not followed up on a number of leads during the investigation, as defence counsel cross-examined her at length before the prosecution formally closed its case.

The sergeant, attached to the Serious Crimes Unit, confirmed that skid marks found at the scene of the killing in Thibou’s had never been investigated, that no forensic analysis had been done on blood spatter, and that no work had been carried out to determine the trajectory of the bullet that killed Christian.

A witness had reported seeing a suspicious white RAV4 travelling at speed near a pond in Royal Gardens and had provided licence plate numbers, those were never checked with the Transport Board. Call records that could have verified a claim made by the prosecution’s key witness about his movements on the day of the killing were also never obtained. When asked about camera footage that had placed that same witness at the scene of Christian’s abandoned truck, the investigator said she had not pursued it because she had been given directives.

Asked by the jury who had issued those directives, on both what leads to pursue and who to charge, she named an Assistant Superintendent of Police who had himself given evidence earlier in the trial.

Saleim Harrigan, 35, Wayne Thomas, 33, and Lasean Bully, 35, are on trial before Justice Rajiv Persaud. They are accused of abducting Christian at gunpoint from his McKinnons home on July 10, 2020, and shooting him dead on a dirt road in Thibou’s that same afternoon. Christian was a senior Customs official who had reportedly been part of a fraud investigation at the time of his death. The trial began on February 19.

Much of the Crown’s case has turned on the testimony of a man who says he transported the three accused on the day of the killing, watched them force Christian into a vehicle at gunpoint, and later directed police to bags hidden at Perry Bay containing clothing and other items believed to have been worn by the killers. The prosecution contends that one of those bags belonged to Christian. His girlfriend identified it by its features and the tea bags and Swiss chocolate found inside, but his mother and brother told police they did not recognise it.

DNA testing found no trace of Christian’s DNA on any of the Perry Bay items, including the bag. When asked whether, after learning this, she had sought any other means of confirming the bag belonged to Christian, the investigator said no. When it was put to her that the bag and its contents had been placed at Perry Bay to create a link to Christian, she said she was not aware of that.

The investigator also confirmed that none of the driver’s statements made any mention of the Perry Bay bag, and that no documentation she was aware of showed the driver had ever been asked to identify the items recovered there. She initially said she recalled the driver mentioning in a statement that he had lent one of the accused a sweater, potentially explaining the driver’s own DNA appearing on a sweatshirt recovered from Cassada Gardens at a likelihood ratio of 33,000, but after reviewing the document, said she could find no such reference.

The driver’s status in the investigation had shifted over time, from person of interest in July 2020, to witness in January 2021, to suspect in April 2021, though he was never charged. The investigator acknowledged that suspects, unlike persons of interest, are placed in cells, and confirmed the driver had at one point been held in one. She also said she did not know whether his movements had been monitored in the days following the killing.

The investigator said she was not aware that an Assistant Commissioner of Police had been receiving information about a threat to Christian’s life three months before his death, that a call had been made to a police officer about the murder before the official report was placed, or that the driver had met with senior officials at a politician’s office. She said she did not know that the driver had offered information about a casino robbery before being released, after which a search warrant for one of the accused’s homes was obtained shortly afterwards.

A DVR found on the seat of Christian’s abandoned truck at Cassada Gardens was never definitively examined, despite a brother of the deceased having told the court that the CCTV recorder had gone missing from Christian’s McKinnons home on the day of the killing, with the kitchen door locks forced.

Questions were also raised about the number of people present at Christian’s home during the abduction. His mother told police she saw four individuals, three in camouflage and one dressed entirely in black. No proper description of the intruders’ clothing had been obtained from her, and her statement contained no reference to a blue coverall or a khaki broad-brimmed hat. Only three men are on trial.

The Crown’s DNA evidence, presented earlier in the trial by an FBI forensic expert, linked the three accused to items recovered from both Perry Bay and Cassada Gardens with significant statistical probability. Harrigan’s DNA appeared on a hat at a likelihood ratio of 7.7 billion and on two gloves at 42 trillion and 49 quadrillion. A shirt linked Thomas at 3.4 octillion. Bully’s DNA appeared on a backpack at ratios ranging from 46 on the exterior to 2,400 on the inner straps and zippers.

When asked by the jury whether she had been satisfied with the investigation before the accused were charged, the investigator said yes. When asked whether the case rested solely on the driver’s account, she said no, pointing to the additional physical and DNA evidence. She also confirmed she did not know how the Perry Bay bags had come to be there.

The defence begins presenting its case on Monday. The prosecution is led by Director of Public Prosecutions Clement Joseph. Harrigan is represented by Wendel Alexander, Thomas by Sherfield Bowen, and Bully by Michael Archibald.