BART police investigating the weekend killing of a passenger on a train in Oakland have no onboard video of the crime, even though the transit agency had what appear to be surveillance cameras just feet from where the suspect shot the victim at close range, The Chronicle has learned.

Although all BART cars have what look like cameras mounted to their ceilings, the vast majority of the devices are decoys incapable of capturing footage, BART officials conceded Wednesday. And some of the actual cameras are broken, two police sources said.

BART police said Wednesday that the suspect in the still-unsolved slaying was recorded before entering the train and after fleeing from it at the West Oakland station Saturday evening. They released clear photos taken by station cameras of a slim, tall man in a green jacket.

However, they released no images from inside the train. BART officials would not say why, but the two police sources, speaking on condition of anonymity, said no such footage exists — possibly because the cameras on the train were decoys.

Director in the dark

The use of such dummy cameras is not common knowledge. Even one member of BART’s Board of Directors said he was unaware of the decoys, and conceded that they amounted to a security gap in the Bay Area’s backbone train system. A spokeswoman for the agency said working cameras will be on every car in BART’s new fleet, the bulk of which will arrive between 2017 and 2021.

At present, what appear to many riders to be sets of four cameras on the ceilings of each BART car are primarily fakes, an effort by agency officials to deter criminals — particularly vandals — without spending money on a more extensive surveillance system for soon-to-be junked cars.

Although BART has many working cameras on platforms and in station lobbies, the fact that cameras inside trains are decoys comes with a cost, as some crimes and key incidents aren’t preserved on film.

For instance, after a BART police officer shot and killed Oscar Grant early on New Year’s Day 2009, investigators could not go back and view video of Grant getting in a scuffle on a train and then being pulled off the car by a second officer. The reason is that no camera on the train recorded the incident.

‘Very robust’

BART police declined to discuss the cameras Wednesday. At a news conference about the Saturday night killing, Police Chief Kenton Rainey said, “If you want to give me more resources, I’ll take them.”

Later, in an interview, Rainey said, “I’m not going to talk about our security system other than it is a very robust system. I don’t know any other jurisdiction that has a robust system like this.”

Even so, BART directors are expected to grill Rainey and General Manager Grace Crunican about surveillance at Thursday’s board meeting in Oakland.

“This is deeply concerning,” said Director Nick Josefowitz of San Francisco, who has been on the board about a year and didn’t know that some train cameras were decoys. “This is something we need to get to the bottom of.”

Suspect’s movements

Rainey called Wednesday’s news conference to release the surveillance photos of the suspect in Saturday’s shooting, in which a man who boarded a San Francisco-bound train at Pittsburg/Bay Point Station shot another male passenger at about 7:40 p.m. as the train pulled into West Oakland.

The photos show the suspect entering Pittsburg/Bay Point Station and exiting West Oakland Station.

The alleged assailant — a slim, tall black man with a shaved head, wearing a green jacket with a hood, a backpack and beige work-style boots — ran from the train after the shooting. He was last seen across the street from West Oakland Station, by the 99 Cents Only store on Seventh Street.

BART police circulated a bulletin with photos of the suspect to other law enforcement agencies in the days after the killing, but did not release the images publicly until Wednesday. Rainey explained that police did not want to influence witnesses’ descriptions of the killer.

No ID for victim

Authorities have struggled to identify the victim. Police said he appeared to be between 19 and 25 years old and was carrying no legitimate identification. The man, who died at the scene, had a knife when he was shot, officials said.

It’s not yet known why the gunman opened fire, or even whether he knew the victim.

Some BART riders expressed shock Wednesday when told of the decoy cameras. As he rode an afternoon train to Oakland for a public meeting on bay wetlands, San Francisco Supervisor Scott Wiener said, “I had no idea.”

He added, “Video on transit is a pretty basic safety issue. When you have a problem, you want to go and find out what happened.”

In 2009, Muni officials in San Francisco came under fire after an 11-year-old boy was stabbed on a city bus. Not all the coach’s cameras were working, and an audit found that surveillance equipment on more than half of Muni buses and trains wasn’t fully operational.

The agency scrambled to fix the problems. “We worked very hard to get better security on Muni,” Wiener said. “It undermined our safety.”

‘Common trick’

Chronicle reporters walked the length of seven BART trains on Wednesday, taking note of the surveillance equipment. In all, 173 of 228 cameras on the cars — or 76 percent — appeared to be dummies.

Gerry Huth, a BART patron waiting for a train at Montgomery Street station, said, “I guess they’re placebos. I’ve worked in warehousing and distribution for 25 years. It’s a common trick.”

But even in his line of work, Huth said, there are usually enough cameras to film an area.

“’If they’re not covering an area properly, that’s unacceptable,” he said. “That’s where it’s a problem.”

BART Director Tom Radulovich of San Francisco, who has been on the board since 1996, said that when the cameras were installed on trains, directors knew some were not real. He said he couldn’t recall the agency’s rationale, but he assumed it was budgetary.

“The thought was that they had a deterrent effect because some people thought they were real,” he said.

Since the Sept. 11 terrorist attacks, more federal money has been available for transit security, he said, and BART has used some to buy new cameras. Radulovich said BART, knowing it was replacing its rail cars, may have chosen to install the new cameras in stations instead of aboard trains.

“I think some of the thinking,” he said, “may have been, ‘We’re going to be getting new cars. Is this a good investment?’”

Evan Sernoffsky, Michael Cabanatuan and Demian Bulwa are San Francisco Chronicle staff writers. E-mail: esernoffsky@sfchronicle.com, mcabanatuan@sfchronicle.com, dbulwa@sfchronicle.com