Kearny police had brought the man to the hospital for treatment on Monday.
Hospital spokesman Mark Robson tells The Jersey Journal the 32-year-old was in a bathroom on the ground floor when he removed a drop-ceiling panel and climbed into the space.
The suspect was captured an hour later.
His name has not been released.
Information from: The Jersey Journal (Jersey City, N.J.), http://www.nj.com/jjournal