Flags flew at half-staff in Sacramento on Wednesday, a day after a BART police sergeant was accidentally shot and killed by a colleague during a search for a stolen laptop and a bag in Dublin - the first time in history a BART officer was killed in the line of duty.
Other police agencies throughout the state covered their badges with black bands for Sgt. Thomas A. Smith, a 23-year veteran of BART whom friends and family called "Tommy." He was in charge of the transit agency's detective unit.
Gov. Jerry Brown said in a statement that he and his wife, Anne, were "saddened to learn" of the death of the veteran San Ramon peace officer, "who bravely served his community for two decades." Attorney General Kamala Harris expressed similar condolences.
During a news conference at BART headquarters on Wednesday, BART Chief of Police Kenton Rainey said he would not name the fellow officer who killed Smith, adding that he is "extremely upset."
"We want to give him a chance to breathe," Rainey said, sometimes choking up with emotion.
A law enforcement officer told NBC Bay Area the officer is 10-year veteran Michael Maes, and like Smith, had a very serious personality. Maes is the BART officer who wrote up the probable cause arrest warrant before the team of officers searched the suspect's one-bedroom apartment in Dublin on suspicion of finding the stolen laptop there, records indicate.
As for members of BART police, Rainey said: "We're in shock, disbelief and numb. Please give us some time."
The 42-year-old Smith leaves behind his wife, Kellie, who is BART police K-9 officer, and his 6-year-old daughter, according Rainey, and documented on the Officer Down Memorial Page, a website dedicated to fallen officers. Smith also has two brothers in law enforcement; one is an Alameda County sheriff's deputy, and the other is a Newark police officer.
Rainey described Smith as a "happy, family man" with a "can-do" attitude.
While this is BART's first fatal friendly-fire shooting since the agency was created in 1972, it also marks the first time in more than a decade that an officer in Alameda County has been killed by a fellow officer. In 2001, two Oakland police officers shot Officer William Wilkins while working as an undercover detective, and the two officers did not realize he was one of their own.
Smith is the first peace officer to die in California in 2014, and his death marks the 36th on-duty officer killed by accidental gunfire in California since 1895.
Rainey offered a few new details about how Smith was killed Tuesday about 2 p.m. at the Park Sierra Apartments, near the intersection of Dougherty Road and Park Sierra.
Smith was one of several plain clothes BART officers and a Dublin police officer searching the apartment of John Henry Lee, a 20-year-old person they knew was in custody. Lee was arrested on Jan. 16 in San Leandro after police say he was trying to steal a car, ran away, crashed the car and then was caught by a police dog.
Lee pleaded not guilty Wednesday to second-degree robbery. (PDF)
Since Lee was on probation, officers were able to search his home without a warrant, and they were looking into a report of a stolen laptop from a BART train, according to Alameda County Sheriff's Sgt. JD Nelson. Two BART officers had cameras on their lapels, but those videos have not been released.
Though they knew Lee wasn't home, the door was unlocked, and they were wearing bullet proof vests and had their guns drawn.
"There's always the possibility that someone else can be in the apartment," Rainey said. "Police work is dangerous. Going into someone else's home is one of the most dangerous things we can do."
Rainey added that he is confident his staff is properly trained. State requires 24 hours of training every two years, but Rainey said BART gives its officers 40 hours of training every year.
No one was actually inside the apartment. And it's unclear what caused Smith's colleague to fire his weapon and fatally wound Smith. The bullet lodged itself near Smith's armpit. Rainey wouldn't disclose the type of weapon used, but said most BART police use Glocks or Sig Sauers.
The BART police department enacted serious reforms in the wake of the controversial shooting of Oscar Grant on a BART platform.
One of those reforms was to require all uniformed BART officers from the rank of sergeant and below are required to wear a tracking camera. Wearing such a camera lapel is optional for plainclothes detectives.
Grant, who was unarmed, was shot and killed by former officer Johnannes Mehserle in the early morning hours of New Year's Day in 2009. Mehserle was later convicted of involuntary manslaughter.
The Tommy Smith Memorial fund has been set up at Wells Fargo Bank. Deposits can be made at any Wells Fargo Bank, Account # 5148561086 under Kellie Smith. Or they can be mailed to:
Tommy Smith Memorial Fund C/O Wells Fargo
11020 Bollinger Canyon Road, Suite 1
San Ramon, CA 94582
NBC Bay Area's Cheryl Hurd, Geoffrey Eisler, Lauren Brennan, Terry McSweeney, Bob Redell, Cheryl Hurd and Kim Tere contributed to this report.