BART Police Sgt. Tom Smith during a 2013 interview. Smith was accidentally shot and killed by a colleague on January 21, 2014. (CBS) BART Police Sgt. Tom Smith during a 2013 interview. Smith was accidentally shot and killed by a colleague on January 21, 2014. (CBS)

DUBLIN (CBS SF) – A Bay Area Rapid Transit police officer was accidentally shot and killed by another officer during a probation search at an apartment complex in Dublin Tuesday afternoon, authorities said.

KPIX 5 learned Tuesday night that the fallen officer has been identified as Sgt. Tom Smith. Sources said Smith had more than 20 years of law enforcement experience.

Smith, 42, comes from a law enforcement family. His wife is a K-9 officer with BART police and Smith’s two brothers are officers at two other Bay Area agencies. Smith leaves behind a young daughter.

Smith is survived by his wife, a K-9 officer with BART police, their young daughter

The shooting occurred just before 2 p.m. at the Park Sierra Apartments at 6450 Dougherty Road, Alameda County sheriff’s Sgt. J.D. Nelson said.

Nelson said several officers went there to search an apartment belonging to a suspect in a series of recent robberies on BART.

The two officers entered the apparently empty apartment and one officer accidentally fired a shot that wounded the other officer, Nelson said.

The wounded officer was taken to Eden Medical Center in Castro Valley, where he succumbed to his injuries, Nelson said.

Smith’s body was taken to the coroner’s office in Oakland, where an autopsy will be performed.

Nelson said he assumes that the officers had their guns drawn as they entered the apartment but that the details of how or why the officer’s gun went off remain unclear.

The suspect was not at home at the time of the shooting.

Dublin police are investigating the shooting.

Nelson told KCBS it’s not unusual for BART police to carry out probation searches and that it’s part of their job.

“It obviously has something to do with a crime that occurred in the BART system and they were just following up on it,” he said.

“City of Dublin has a contract with the sheriff’s office,” Nelson said, adding that it is normal protocol for them to have an officer at the scene with the BART officers.