The couple lived at 10026 Garis Shop Road in a trailer behind a white house occupied by the Suzanne Garde's parents and her 16-year-old daughter.
On the night of the shooting, Garde and his wife were arguing after he learned she was seeing another man, Michael said.
Garde later told Washington County sheriff's deputies he was going to go after the "other man" when he and his wife struggled over the shotgun in the driveway.
A neighbor told deputies he heard two shots. Suzanne Garde's mother reported looking out her window and seeing the flash of light from a shotgun blast, Michael said.
According to an autopsy report, Suzanne Garde was shot in the chest and in the back, Michael said.
The hospital notified the deputies that Suzanne Garde died at 2:52 a.m. on May 6.
Deputy Tom Routzahn, the first officer to arrive, saw Suzanne Garde lying face down near a bush next to the trailer, court records said.
Routzahn said he ran to Suzanne Garde and dragged her across the stone driveway, and a Community Rescue Service rescue worker helped get her into an ambulance.
She told Routzahn her husband had shot her, Michael said.
Routzahn said he was told by witnesses to look for Garde's black Pontiac LeMans. By the time he reached the driveway, the car was gone, he said.
Garde surrendered at the Maryland State Police barracks a short time later.