A police inspector and sergeant gave a firearms suspect a lift home with a stun gun in his jeans pocket.
Officers were looking for Lee Narwan, 28, because his mother feared he had a weapon and would harm himself.
But after finding him in the street, Inspector Karen McColl and Sergeant Lorraine Fraser gave him a “cursory search”, put him in their car and drove him home.
The gun was only found after they arrived, when Sergeant Fraser saw him try to hide it in a washing machine.
Narwan, of Thorntonhall, near Glasgow, is now on bail awaiting sentence after being convicted of possessing a prohibited weapon.
At Hamilton Sheriff Court, Inspector McColl, 49, admitted she was “embarrassed” when the gun was finally discovered.
She added: “We were unable, because we are female, to carry out a full search. It was only a cursory search, patting down his jacket and jeans.”
Jim O’Dowd, defending, said that was astonishing. Ms McColl replied: “He was agitated and emotional, and it was extremely cold and snowing.
“We had requested assistance from other, male officers.”
Narwan is due to be sentenced on December 8.