Plus it's usually their friend that is murdered. They tend to get ****.
@Dave :
I'm assuming this is the real reason.
While CJ's thought makes sense, I don't think that much thought is put into it.
Anne's reasoning of federal doesn't really work since there are plenty of murders (and other crimes) under federal jurisdiction that don't result in all out manhunts - see the FBI's most wanted list.
Why shouldn't as much effort be put into finding the person who shot that little kid in his bed a few years ago in the East Bluff(?) versus someone who shot a police officer? The kid gets a couple detectives asking some questions. The cop gets thousands of man hours in a very short time frame. When small children can't even sleep in their beds, isn't that a possible definition of anarchy?