MILWAUKEE (CBS 58) -- The owner of a Picasso has a theory about who stole the artwork from a Milwaukee art appraiser. 

The artwork was stolen last month fromDeLind Fine Art Appraisals, LLC.

It's worth between $35 and $50 thousand dollars.

The artwork's owner says there was a more valuable piece of art that was overlooked by the thief.

 "We believe this was either a crime of opportunity or the Picasso was purposely targeted because it was in display at the window and you could clearly see it from outside," said Michael Goforth, co-owner at DeLind Fine Art Appraisals.

Goforth says they are upgrading including new cameras and having a person on the building's first floor.

There is a $5,000 reward for the return of the Picasso.