The director of the Taunton Public Library says she's dumbfounded that someone would leave chicken feet and rotting fish around the building.
A custodian found the animal parts on Saturday at various locations, including the front steps and in a book donation bin.
He reported the prank to Director Susanne Costa Duquette on Monday, and she notified police.
Duquette tells The Taunton Daily Gazette that closed-circuit video shows two young men in hoodies carrying something up the steps after closing on Friday and putting something near the door. That pair met two others wearing hoodies, and the group walked toward the donation bin.
Duquette says the library has had trouble with disruptive youth and suspects the prank was pulled by kids getting revenge for being asked to leave the library.