White residue found on the gun used to kill supervising Fire Marshal Douglas Mercereau tested out as salt

White residue found on the gun used to kill supervising Fire Marshal Douglas Mercereau tested out as salt, a forensics scientist told jurors today.But former NYPD criminalist Kristen McDonald didn't know where the salt came from, or how the murdered fire marshal's stainless Smith & Wesson 9mm service weapon wound up with rust inside the slide, behind the muzzle and in front of the trigger guard."The source [of the white residue] cannot be conducively determined," Ms. McDonald testified as to what she wrote in her report that documented her findings.No tests were conducted on the rust found on the gun, Ms. McDonald said.
Prosecutors charge that Janet Redmond-Mercereau shot her husband three times in the head with his service pistol as he slept in his bed inside their Oakwood home on Dec. 2, 2007, then tried to cover her tracks by running the gun through a dishwasher to wash away prints.On Monday, Crime Scene Unit Detective Charles Reiss told jurors he lifted a print from the empty magazine inside the murder weapon. The print was sent to the Department's Major Case lab for analysis, but so far test results of that print have not come out during trial.Defense attorneys Mario Gallucci and Joseph Benfante maintain the print does not belong to Mrs. Redmond-Mercereau.
Today, Benfante attempted to pin the source of the rust on investigators' handling of the weapon after it was recovered following the shooting.