As of Sunday night, two men have died at the hands of BART police in less than three years. At 9:34 p.m. on July 3, two officers responded to a call about a man with an open bottle of alcohol at San Francisco’s Civic Center station. Eleven minutes later the BART police arrived on the scene. Within one minute, the man described by a witness as a “wobbly drunk” had been shot in the torso. An hour after that he was declared dead at San Francisco General.

It’s easy to want to compare the incident to that of Oscar Grant’s murder on New Year’s day in 2009, but the details are little different. Grant was unarmed and shot at point blank while lying face down on the Fruitvale station platform. Sunday’s victim (police are withholding his identity until they can contact family) was holding a knife as well as a bottle, which he allegedly hurled at the two BART officers upon their arrival. Grant’s killer, former officer Johannes Mehserle (who was released after serving half of his two year sentence for manslaughter) claims his intent was to use his Taser, not his pistol, on the subdued BART rider. This weekend, despite being in a crowded public place, discharging three bullets was no accident; one officer carried a Taser but never reached for it. Oscar Grant was a young Black male. The man killed on the eve of the 4th of July was white.

Despite their differences, both killings prompt the same question: Why? Why was deadly forced used at a heavily populated BART station? The man had a knife, but who was in danger? BART passengers? The officers? The details are still forthcoming, but BART officials and the San Francisco Police Department, who are heading the investigation, must now explain as much as possible to a public already wary of the discretion of BART Police.

While Oscar Grant’s shooting was captured by shaky cell phone videos, the sole footage of Sunday’s incident comes from security cameras that only got a partial view.“ The two officers involved, one who has worked for BART for six years, the other about 18 months, have been placed on administrative leave, but neither has been identified.

BART Police Chief Kenton Rainey said that from what he knows, he’s “comfortable with what has occurred.” Until we know more, that’s what’s concerning.