[roscorollo]

I've looked into this before, following the same question you had. The most logical answer I found was the criminal version of an insurance policy.

Basically they would steal said artwork but instead of selling, the point is to keep it in hidden storage. Then if at some point further down the line the criminal gets arrested in relation to another crime, they use the location of the artwork as leverage during plea bargaining.

This is one of the major theories in the Isabella Stewart Gardner Museum heists in the 90's.

[tonyedgecombe]

I think this was going on with the mafia because the Italian legal system was conducive to it.