Legendary drug dealer turned witness protection dropout Alpo Martinez was gunned down in Harlem on Halloween night.

If the police have any idea who killed the convicted murderer, they aren't letting on.

In absence of any named suspected, speculation on why the killing went down is ripe.

According to Lewiston Sun Journal (Alpo had been living in Lewiston, Maine while he was in witness protection), there are three main theories.

Most of the speculation surrounding his murder focuses on the reality that Martinez ratted out others in the drug business, leaving family and friends who might have harbored grievances deep enough to want to see him dead.

But there are other theories floating around that include miffed boyfriends angry that Martinez paid too much attention to certain women. Some wonder if Martinez is even dead, if the whole Halloween shooting was somehow staged.

So far, there are no credible theories that involve Alpo's apparent love of "fat butt boys."