Dover-Foxcroft Police Chief Ryan Reardon said the moose was spotted walking down Park Street a little after 1 a.m. Friday.
He said it apparently got spooked and crashed through the window of an empty storefront on Main Street.
Chief Reardon said it wandered around inside for a few minutes and came back out the window just as law enforcement arrived on the scene.
The chief said the suspect in the break-in is not in custody.
The moose was last seen leaving east Main Street.