Several hours after Pittsburgh police first attempted to serve a warrant at a Carrick duplex yesterday, a SWAT team forcibly entered the building and arrested a Philadelphia man they believed to be wanted on felony drug charges.

"We thought we had our bad guy," said SWAT team leader Steve Mescan.

But about 10 minutes later, a methodical search of the apartment unearthed Julius Postell, "the real bad guy," hiding behind a piece of plywood in a closet crawl space.

Both men were arrested and transported to the Allegheny County Jail yesterday, with Raishaad Taris Waters, 24, charged with eluding police officers and harboring a fugitive and Mr. Postell, 33, charged on the felony drug counts.

Neither man was armed at the time of arrest, said police spokeswoman Diane Richard, though police were planning to search the apartment for weapons and drugs.

The scene unfolded directly across The Boulevard from Quentin Roosevelt Elementary School, which was put on lockdown for nearly four hours yesterday.

Donald Diggins of Bon Air was one of a group of parents waiting nervously in the rain for hours, hoping to get their children out of school at Roosevelt.

When he finally picked up 6-year-old Haile from kindergarten around 2 p.m., "I was more teary-eyed than she was," he said. "I'm cold, wet, but I got my baby."

Acting on a tip from Philadelphia police, Pittsburgh police attempted to serve the warrant at 10:10 a.m., said Ms. Richard.

Police observed the window shade being lifted and lowered, but nobody came to the door at the brick duplex apartment, she said. Shortly after a police SWAT team arrived on the scene, a woman in the upper duplex apartment with a history of heart trouble called 911 complaining of chest pains.

Police had to first get her out of the house safely and transport her to a hospital before resuming the attempt to serve the warrant on Mr. Postell, said Ms. Richard.

After unsuccessful negotiations to get someone to open the door of the downstairs duplex apartment, police forcibly entered at 12:15, said Mr. Mescan, and apprehended Mr. Waters, who told them that there was nobody else home.

About 10 minutes later, they found Mr. Postell hiding in the closet and determined that Mr. Waters had likely helped hide him there using the plywood. The apartment had a strong odor of marijuana, said Ms. Richard.

She said police did not know how the men were connected to the Carrick duplex.

Mr. Postell was an inmate at the State Correctional Institution Pittsburgh in 2001, and he and two other inmates were charged in connection with the heroin overdose death of another inmate, Matthew Schreckengost of Kittanning.

He pleaded guilty in 2004 to 11 drug trafficking counts and was sentenced to 18 months to three years more in prison, plus three years' probation.

The owner of the property, Emilia Folino of Bethel Park, said that she has rented the downstairs apartment for the last four or five years to a woman with two children. She declined to provide the woman's name, but said that she pays the rent on time and has never been any trouble.

She has no idea whether or how the woman is connected with Mr. Postell or Mr. Waters.