SALT LAKE CITY -

The FBI wants the public's help in finding a man who is sexually abusing a child.

The bureau says "John Doe 28" is seen in images and video "engaging in sexually explicit activities with a child." These came to the attention of the National Center for Missing and Exploited Children in November 2012.

Authorities said John Doe 28's state and region are unknown, and is asking the public's help in identifying him.

The FBI believes enhanced images of the man offer several clues. The video shows him and the child inside a home with what appears to be a blue sofa chair and a picture hanging on a wall in the background. Additionally, the man is wearing wire-framed glasses and a burgundy T-shirt with what appears to be a shark logo on his left side.

John Doe 28 appears to be white and in his 30s or 40s.

If you have any information on this case, submit a tip at https://tips.fbi.gov or call the FBI’s toll-free tip line at (800) CALL-FBI ((800) 225-5324).