It seems like BART Police always misses the crook by seconds
Yesterday, I was at North Concord BART station. There was a guy in a small red truck by the dumpster. I could tell he had his pants down. As I parked, he got up from the passenger seat pulled his pants up and took off in hurry. Not a minute later, BART Police cruises the lot. I disappointed, they didn't catch this guy with his pants down doing whatever it was he was doing in his passenger seat. They need to get rid of the dumpster in that parking lot. At about 12:30 a.m., when they think BART is closed, people start parking behind there.

Did you actually see this
Did you actually see this guy's pants down or are you speculating? Was he actually committing an illegal act, or what he just changing his clothes? If you truly witnessed a crime, you have the right to make a citizen's arrest for any crimes that are committed in your presense.
If catching this guy was really a priority, you could have told the BART cop that pulled in the lot.
If you witness a crime and actually want to make a citizen's arrest, be prepared to be patient with the officer while they take a statement from you. There is no point to telling an officer about a crime you witnessed, and then leaving without providing a statement. A police officer cannot cite/arrest someone just because you gave them a quick report of what happened and then leave without giving them your information.
I saw his pants down from my
I saw his pants down from my car. The BART officer was a ways away from me and of course, I'm running for the train. I see this all the time so it doesn't exactly freak me out. I just was pointing out that BART Police never has the timing to catch the crook in the act. Now, if I saw a car theft, etc., going on, you better believe I would do something about it. It isn't worth it to me to make a citizens arrest and miss my train over some guy whacking off when this is a daily occurrence at BART and on the trains, as well as drug use and dealing in the lots. Also, the three times I have tried to deal with BART Police, I have found it 100% useless. They could care less about me and my car and whether it gets vandalized or stuff gets stolen out of it as i foud out the hard way. very frustrating. so, why bother.