Because no one was living there and there are plenty of weirdo's who might like to prowl about the scene of a murder. Correction to my last post though, I don't think a PB was installed at the farm - one was installed at the caravan park after the robbery. JUST an alarm was installed at WHF - for OBVIOUS reasons.
Yes people love to go break into unoccupied places especially if something bad happened there or reports of hauntings and to steal. As of the past 15 years though stealing has gone to new levels with people breaking in to strip pipes and wiring from houses. It is bad enough stealing design features but to bust all the walls open and steal the guts is even more horrific and then there are the firebugs...
I have explored abandoned places before (long term abandoned not simply unoccupied for a short period) it is fun. I also have a collection of hotel keys to rooms infamous for murder having taken place there. (Yes I know I collect some odd things) Many of the hotels no longer exist but it is still interesting to see the key that went to that room. I think the most interesting key I have pertains to the following murder since the key was used by the murderer:
http://www.mysteriouschicagoblog.com/2012/12/the-woman-in-black-at-drake-hotel.htmlI only bought one of them sadly I didn't know the full story till later. Whether the key I have is the one that belonged to the victim or used by the killer there is no way to know which is why I should have bought both but I didn't the other lot of keys sold before I could also buy it and that's that. The other purchaser might not even be aware of the significance of that particular key from the lot.
With the exception of a Key to Dahmer's Ambassador Hotel room, all my murder keys are pre-1960. The point anyway is if I just collect keys you know there is some freak out there who will want to steal items from a murder site not simply wander around the house gawking.