There is a reason why many police officers do not like to be photographed and recorded while on duty. It has a lot to do with evidence, proof, irrefutable statements to community, and with accountability. Police officers often are not fond of answering to the communities they serve when they abuse others, and in some communities, racism and bigotry replace the law. Freddy Gray's spine was crushed during an arrest in Baltimore, Maryland. He later died, and police in Baltimore have admitted that there wasn't actually a reason to arrest Mr. Gray. There are statements from five of his assailants, but one of them refused to cooperate, citing his fifth amendment rights against self incrimination. Fortunately, one of Mr. Gray's friends turned on his cell phone camera and began filming.
And, for your reading pleasure, here's a list of the names of the officers who were involved in Gray's untimely death. Rest in peace, Freddie Gray.