SAN ANTONIO - The San Antonio Police Department has posted a photo of a man on its Facebook page, saying "he might have information on the murder" of Det. Benjamin Marconi. Police are asking for assistance in identifying the man shown wearing a hat and walking in the photo.

Marconi was fatally shot late Sunday morning while writing a ticket in his squad car.

Chief William McManus says an unknown suspect shot 50-year-old Marconi twice in the head. Marconi was a 20-year veteran of the force.

McManus said the officer had pulled over a vehicle and while he was inside his squad car writing a ticket, a vehicle pulled up behind him. He says the driver of that vehicle then walked up to the officer's driver-side window and opened fire.

He says he does not believe the original motorist pulled over had any relationship to the shooter.