finding peoples wallets

So in a locker we got from people who spent a lot of time incarcerated we find wallets.  Several complete wallets, ID credit cards etc.  None of the names match the contents.  Now yes I know, lots of you would just toss them and forget about it.  But I was curious.

So I tried taking them to the police.  "Where did you find them?"  In a locker in a city 40 miles away "Take them there, or contact the owners".  Really? 

So I hunt down a owner curious to the story.  She had lost it a year ago, asked me to shred it.  So shredding away.  Ditto for the second one.  And the third one. 

pick pockets?  Or just casual theft of wallets?  I will never know...