MINNEAPOLIS (AP) — When Philando Castile was shot by a police officer, his girlfriend broadcast his final moments live on Facebook. But experts say the footage from a squad car camera was probably a bigger factor in prosecutors' decision to charge the officer with manslaughter.

And that footage is still no guarantee that Jeronimo Yanez will be convicted, as other police shootings have shown.

Philip Stinson is a criminologist at Bowling Green State University who tracks fatal police shootings. He says video sometimes raises more questions and results in an acquittal or a hung jury.

Since 2005, a total of 78 officers have been charged with murder or manslaughter. Of that number, about a third of the defendants were convicted — 14 by juries and 13 through guilty pleas.