There was a letter to the editor in the SF Chronicle today that talks about guns and tasers. Evidently, in this case, it might very well be he thought he had the taser.

Sarah- Glad you are home safely.

When we were out riding (about 50 miles from Oakland) there was a lady standing on a corner with a sign that read: "We are all Oscar Grant" (name of guy that was killed). It has affected many people, not just the folks in Oakland. I'm sorry it happened as well. BART could be adversely impacted by this incident for a long while by angry people.