SAN FRANCISCO, CA (KRON) — The FBI is looking for a man accused of making threats against law enforcement.

The FBI says Shawn Frederick Weatherhead, 45, is a transient, with a distinctive “dork” tattoo on his neck.

Weatherhead has ties to Oregon and Nevada where he’s been making threatening calls to the FBI’s public access line located in Clarksburg, West Virginia. The FBI says he’s also made violent threats against law enforcement elsewhere across the United States and is known to carry a switch-blade knife.

He is also thought to be using illegal narcotics.

Here is the full flyer from the FBI. If you spot him, do not approach him as he’s considered armed and dangerous. You should instead call 911 immediately.