Some people will collect anything. But, this auction is just offering some stuff he owned, not something used in the crimes. He worked as a security guard and was arrested on the job. His girlfriend ended up with it and she pawned it at the time for what anyone would have gotten.
While I'd have no problem owning it, I'd only pay what it's worth as a shooter--objects don't have karma, and this has no particular historical significance.
It will be interesting to see what this actually bringsl.