Police almost always protect their own against horrendous acts, but it is unusual for them to close ranks around a wanna-be cop. In fact, in my experience, police cannot stand wanna-be's and their constant annoyance. This is why it seems so unusual for the Sanford cops to be protecting this guy.
I just read an article where it all starts to become clear. From LA Times article http://www.latimes.com/...
“The portrayal of George Zimmerman in the media, as well as the series of events that led to the tragic shooting, are false and extremely misleading,” wrote his father, Robert, a retired magistrate judge, in a letter published in the Orlando Sentinel.
Emphasis is mine. Now, I could be wrong but I would bet that the retired judge father has some sort of political connections to the police or their supervisors.
Of course, it could just be that these cops are pig-headed, bumbling, racist idiots and at this point just cannot admit that they were wrong thinking that no one would care about a murdered black kid.