BART riders might not realize it, but the transit system's police department has the ability to keep a near-constant electronic eye on them with a comprehensive surveillance network.
Thousands of security cameras are spread out across all 48 stations, and on Monday, NBC Bay Area took an inside look at the the room where police manage hours of surveillance video.
The surveillance room at BART Police headquarters, near the Lake Merritt Station, receives footage from 4,000 cameras that record everything going on in the system 24/7.
"We love our cameras in here," said Aliyyah Shaw, BART Community Service Officer, who showed monitors for a number of cameras.
One minute, she’s looking over a rider as he waits for his train to arrive at the Civic Center station. The next minute, she’s zooming into a license plate of a vehicle parked outside of BART police headquarters in Oakland.
When a crime happens in a BART station or parking lot, Shaw sifts through hours of video footage and hunts down a suspect, camera angle by camera angle.
"I love catching the bad guys," she said. "It’s the best thing when you can identify the suspect. You can help the detectives capture somebody who has done something wrong; that’s the most rewarding thing."
Shaw felt that way this summer, when she was able to track the movements of John Lee Cowell, before and after he allegedly killed 18-year-old Nia Wilson at the MacArthur BART station.
"After I saw the incident, I knew who to look for," she said.
BART Police can’t physically monitor each surveillance video live, but they plan on expanding their digital network of cameras and are adding more officers to the unit.
BART rider Bruce Maxwell remembers the last time he felt scared for his safety while riding the train.
"A couple of guys tried to intimidate me to get some money," he recalled.
Maxwell said he's a little concerned about privacy, and a camera isn’t the same as a police officer. But, he added, it all comes down to how police follow up with the footage.
"I don’t know if cameras are going to stop that, but if they were more aggressive, it might be helpful," he said.
BART's cameras do not use facial recognition technology, and not all of them are digital HD cameras. Some are still analog.
BART says it’s going to take four and a half years and $15 million to create a full HD digital surveillance system.