06/22/2004 at 04:15 PM EDT
Modesto Police Detective Allan Brocchini took the stand in the double-murder trial of Scott Peterson on Tuesday, testifying that Scott was "calm, cool and relaxed" while being interviewed about the disappearance of wife Laci Peterson.
The detective watched as prosecutors played back a video of the midnight questioning session between Brocchini and Peterson on Christmas 2002, after Peterson's pregnant wife, Laci, was the subject of "suspicious missing person" report.
Brocchini's courtroom appearance, which was expected to take up most of Tuesday, followed Monday's session in which a string of Laci Peterson's friends testified that Laci had stopped walking her dog weeks before she vanished.
Their testimony countered the defense theory that Laci may have been abducted while out walking.
Brocchini's interview with Scott took place in a Modesto police interrogation room and showed the detective asking Peterson questions about his activities during the day. These included questions about fishing, the placement and condition of items in Peterson's home (such as why the floor mop was more wet than it had been a day after the maid's visit) and why the Peterson dog arrived home with its leash on.
On the stand, Brocchini also reviewed the cell phone calls Scott made during the day, including one call Peterson said he made to Laci to tell her he was going to be late.
On the video, Peterson said he went fishing near an island in Berkeley and trolled for 90 minutes. He also said he had a gun in the glove compartment of his vehicle, prompting the detective to request Peterson take a gunpowder residue test, to which Peterson submitted.
Before taking the test, Peterson asked the detective if exhaust from his outboard motor boat would show up in the results, Brocchini said.
Peterson, 31, claims he left his pregnant wife at home to go on a solo fishing trip and returned to an empty house. Prosecutors charge the former fertilizer salesman with murdering his wife and their unborn son on or around Dec. 24, 2002, and dumping the remains into San Francisco Bay. Peterson has pleaded not guilty to all counts.
On Tuesday, after seeing the courtroom video of Scott's questioning by Brocchini, Scott's sister-in-law, Janey Peterson, told PEOPLE: "Everything (Scott) said on the tape was the truth. He was absolutely cooperative. There's nothing there."