PITTSBURGH (WPXI)— One man is facing federal charges in connection with last weekend’s protests that turned into rioting and looting in Pittsburgh. Now, police are asking for help finding another man. Investigators said they are looking for the man in connection with tossing an “improvised incendiary device” at officers near Mellon Square on May 30. The device exploded on the ground and an officer suffered concussion-like symptoms. Police said this is part of an investigation with a newly formed task force between local agencies, the FBI and ATF. If you know who the man is, where he might be located or have additional pictures or video, you’re asked to contact the Damage Assessment Accountability Taskforce at DAAT@pittsburghpa.gov or call 412-323-7800 and ask for the task force. You can remain anonymous.