Now, the US has a high Murder solution rate, but it is a rate driven by the fact that almost all murders are done by friends or relatives (And remember the term "Friends" mean everyone who you deal with just the people you consider friends). Thus as the overall murder rates drop, as less and less people kill their friends and relatives, the solution rate for Murder declined even more, as you see an increase in murders by people who do know each other, or whose connections with each other are few.
The Decline Murder Solution rate:
http://www.informationliberation.com/index.php?id=26784Thus the reason the Police have not done anything, is that there is nothing they can do. If someone finds a body the first thing the Police will do is see who was around the body (including looking at the person who found the body), once those people are excluded (For example when a Hunter finds a body in the Fall when it was clear the body was killed in the Spring, when the Hunter was NOT even in the county the body was found in) then the police look at his friends, co-workers, enemies and relatives. If this turns out to lead no where, then where do the Police go? In this case the police may look into all the Anti-Government groups in the area, but that may also lead no where. The Police may then look at people performing illegal acts (such as raising Marijuana) but when that leads no where. the police have no where to go.
Lets be honest most Murderers are picked up within one to two days of the Murder do to the fact, their are either a Friend or Relatives of the Victim, someone the Victim dealt with on a frequent basis OR the victim was just in the wrong place at the wrong time when he came across the wrong group (The Anti_Government groups and Criminal groups fit this profile). The police connect the evidence at the crime scene with someone in one of these groups (and often time with people who are in more then one of these groups, for example a relatives who is raising Marijuana to finance an Anti-Government Militia).
No one is pointing to any of the Victim's relatives. No one is pointing to a Friend or Co-worker or even an enemy of the Victim. That leaves wither a member of an Anti-Government group or a Criminal Group, but no evidence points to any SPECIFIC group (the writing can be from either group or even from someone else trying to get the investigation sidelines on such groups as opposed to who really did the crime).
Lets be honest, two people could have told us who did this crime. One of them (The Victim) is unable to talk and the other one may just be keeping his month shut. If that is the case, all we have is a body and whatever evidence the police found around the body and from what I have read that leads to no one in particular. The best thing the police can do is to gather whatever evidence they can, investigate, ask questions and see who starts bragging about killing a Federal Agent. That may take years before we have any idea who did this crime and even longer to collect enough evidence to convict someone. Thus the best thing the police can do is keep quiet and do their job.