Was Oakland's moment of silence for Ferguson buzzed by a police helicopter?

http://www.sfbg.com/politics/2014/08/14/was-oaklands-moment-silence-ferguson-buzzed-police-helicopter

But as hundreds of peaceful demonstrators in Oakland's Frank Ogawa Plaza took part in the National Moment of Silence in honor of Brown, that quiet was disrupted by the loud chop-chop-chop of a helicopter hovering directly overhead.

"Helicopter circling #Oakland #NMOS14 apparently didn't get the memo this will be a silent vigil," tweeted Sigrid Hafstrom, an Oakland resident. Many tweeted and spoke about the disrespect of the hovering chopper.

Some reports are now identifying that helicopter as a California Highway Patrol aircraft, which begs the question: Did state cops buzz over a memorial for those who died at the hand of police?