“These are tactics terrorists use in the Middle East. They will hide bricks in piles in buildings and so forth. They will move into the area start their little protests. Then they will find their pile of bricks and pipes and start busting out windows,” said Bill Warner, a private investigator who tracks and researches radical groups around the world.
The Star Tribune reported that “other ‘suspicious’ items” were also found on the rooftop.
Read more at Examiner.com