The trial of customs officer Claude Terry continued on Wednesday, with jurors hearing a taped interview in which he answered questions about a firearm found in a plastic box in the water tank behind his Cayman Brac apartment on Aug. 23, 2016.

Mr. Terry is charged with possessing the firearm – a Smith & Wesson revolver and eight rounds of .44 Magnum ammunition – without a license. He pleaded not guilty and the matter is being heard by a jury of five women and two men, with Justice Michael Wood presiding.

The case for the prosecution, conducted by Crown counsel Kenneth Ferguson, is that the gun had been held at the Customs office on the Brac, but went missing.

The box with the gun in it was recovered from the water tank by Inspector Wendy Parchment, after an employee of the apartment owner saw the box when he went to pump the water out.

Mr. Terry explained in his interview that he knew the individual water tanks for the apartments were being removed because the units had been connected to the Water Authority supply. He said he still had water in his tank and got some out on the Saturday, Aug. 20, in order to mop his floors.

He was on vacation that week and was home when he heard voices outside by the tank on the Tuesday. He saw Ms. Parchment and the landlord and he thought they were talking about her buying the tank or being given it.

Mr. Terry said he went outside and asked if they had seen his case. He explained that, after mopping on Saturday, he had taken his phone out of its case because he wanted to submerge the phone in water to test if it was waterproof. He said it seemed to work, so he put the cover back on the water tank, not realizing the phone case had fallen inside. When he did realize, he decided he was not going into the tank to get it.

He denied asking the officer and landlord if they had seen his “box.” He told his interviewers, “I never used the word ‘box.’” He said he had no idea they were at the premises for any reason other than Ms. Parchment getting the tank.

He said he did recognize the gray box, but had not seen it for about two years.

It had been used to carry hand tools aboard vessels for repairs at sea. The box had been kept in the boat shed on the district administration compound, but the shed was not secure.

Mr. Terry said he also recognized the firearm. It had been under Customs control, but had gone missing over a year earlier. He said he had handled it at the Customs office when he was moving things around in a weapons storage cabinet to make more room. “I saw the gun all the time with the rest of my co-workers,” he said.

Asked whether members of the public would have had access to where firearms were kept, he said they should not have access, but in the Brac, things were so “lackadaisical” and he referred to a back-door access.

Asked if he knew anyone who would want to put the firearm in his water tank, he said he could think of a long list. He said he had felt unjustly targeted over the past few months and had received animosity. He noted that his dog had been poisoned earlier that month.

Also on Wednesday, jurors heard from forensic DNA scientist Angela Tanzillo-Swarts. She explained that she had examined various swabs from parts of the gun and had found multiple-source DNA profiles. For example, on the grip of the gun, she found a profile containing DNA from at least two individuals. Mr. Terry could not be excluded as a contributor, she said.

Asked how long DNA could remain on an item, she said that if the environment was good, it could last for years. “Our techniques are becoming more and more sensitive,” she noted.

Defense attorney Crister Brady asked if an item were wet or moist, could DNA survive three or four days? The witness said it would depend on the amount of moisture present. Previous witnesses have said the box containing the firearm was found suspended by a cord from the water tank cover and kept afloat by a buoy.