The other is for searches, mainly in enclosed spaces, where the dog's sense of smell can aid in finding a hidden human suspect.
"But there's also a perception that a snarling dog can intimidate people, which creates a lot more potential for trouble."
The first BART Police canine corps dates back to the early 1970s. But the BART Board disbanded the program in 1975, after a police dog on a train in Philadelphia barked at BART Director John Glenn.
In 1990, Police Chief Harold Taylor restored four dogs to the force, saying they would be "a strong statement of police presence," would deter violent crime, and could be used to help clear homeless people from trains and stations. In an interview last week, Taylor said the dogs, which now number nine, are used "to back up officers, in all their law-enforcement duties."
The dogs, imported German shepherds, are bred and undergo Schützhund training at a special school in Germany, where they learn to attack on command. "The dogs only [understand] German," explained Deputy Chief Kevin Sharp. "The officers learn to issue their commands in that language."
Sharp said none of the BART dogs are trained to sniff out bombs or drugs and that they aren't often needed for searches. In normal situations, he said, the dogs stay in the police car, with the window open, while the officer approaches a suspect. "They're trained to jump out and attack without any command if they see that the officer is under assault," he added.
ACLU Police Practices lawyer John Crew found that description alarming. "In other words," he said, "we have dogs deciding on their own when to use what amounts to lethal force. That's not a very good idea."
Avenzino said the training methods used for such dogs "are, to put it mildly, controversial. A dog will do anything to please its owner; if you teach it to attack on command, it's like loading a gun. In my opinion, it's very dangerous."
Jim Chanin, a Berkeley lawyer who has filed several lawsuits over attacks by police dogs, said he sees no good reason for BART to have a canine corps. "The problem is that these dogs are just trained to attack," he explained. "You can't use them to search for some kid lost in the BART tunnel.
"If there's something the BART police do on a regular basis that requires the use of dogs, I certainly can't see what it is."
Chief Taylor told the Bay Guardian that dogs provide much less expensive backup than additional sworn officers. Berkeley Police Lt. Tom Grant said he agrees, to a point: "But then you have to pay out those big legal settlements if one of the dogs does something wrong."