Code of Silence
When an officer is in trouble on the job or in trouble with his wife or girlfriend at home, he counts on his buddies to cover for him. He gives them a story that explains why he "had to do" whatever he did.
Whether or not they personally condone his behavior, they may rationalize his behavior, saying he was stressed out, under a lot of pressure, or quite simply, that he's only human. They repeat his version of the story and they stick to that version. They put themselves on the line with their fellow officer.
Whether testifying in court or smoothing things out at home, the rules are simple for them:
Say as little as possible.
Answer only the question asked.
Don't give details.
Deny all accusations.
Say "I don't remember, I didn't see that, or I don't know.