A spokeswoman for the state Department of Public Welfare said Martinez was being held by Montgomery County Emergency Services, a nonprofit agency that leases a building on the grounds of Norristown State Hospital.
Martinez appears to have gotten through two secure areas and out the front door of the hospital, Kelly said.
"He initially ran into the Farm Park, into the cornstalks," Kelly said. There, police found a Flyers sweatshirt they believe he discarded.
He is believed to have exited the park around Sturgis Street and may be headed west.
"He has family in the Lower Salford or Pottstown area," Kelly said.
Sheriff's dogs were unable to pick up his scent once he left the park, so "he may have gotten into a vehicle or a bus," Kelly said. "Once he got out of the perimeter, all you can do is put out a be-on-the-lookout notice" to the other police departments.
Roughly two minutes after the escape call, 911 dispatchers received another call from the park - a suicide.
Sgt. David Boyer of the East Norriton Police Department, which is responsible for that part of the park, said some people walking along the trail saw a man sitting on a bench, looking at his cellphone. "Once they passed, they heard a gunshot," he said.
Boyer said the victim was a 54-year-old man from West Norriton Township. His identity was being withheld pending notification of his family.
The 690-acre park is owned by the state Department of Conservation and Natural Resources and split among four law enforcement jurisdictions - East Norriton, West Norriton, Norristown, and the State Police.