After finding a suitcase in an alley early yesterday and opening it up to discover a "little black box that had a wire," Mark A. Wade notified authorities. For his trouble, the homeless man later was detained for hours on an outstanding warrant for aggressive panhandling.

Wade flagged down a U.S. Secret Service car in the pre-dawn darkness, leading to a nearly four-hour traffic tie-up as law enforcement officials checked out and then shot open the suitcase that Wade had found in the alley next to the Crowne Plaza Hotel at 1001 14th St. NW. Four hundred guests from the fully booked hotel were evacuated to Franklin Square across the street, after being awakened at 5:30 a.m. by the hotel fire alarm and an intercom announcement.

Police split open the suitcase with a high-pressure water cannon and determined that there was no explosive device. But from 5:30 until shortly after 9 a.m., traffic was closed in a two-block radius around the hotel. Metro buses also were delayed, and traffic congestion stretched down Interstate 395 into Virginia.

Wade, 35, said in an interview that he was rummaging for food in the alley when he came across the suitcase. Believing it might have been left by a hotel guest, he said, Wade shook the suitcase and opened the latch.

"I noticed this container that looked like a fire extinguisher, with two little holes that looked like pressure valves," Wade said. "There was this little black box that had a wire" passing into it. When Wade tried to remove the container, a red light and loud alarm went off.

Wade said he "slammed the case, ran out into the street" and flagged down a passing Secret Service car.

Wade's account was confirmed by law enforcement officials.

Units from the D.C. police and fire departments, the FBI, the Bureau of Alcohol, Tobacco and Firearms and the Secret Service responded. Police technicians X-rayed the suitcase, revealing a cylindrical tube and wires.

"It was highly suspicious, to say the least," D.C. Police Chief Charles H. Ramsey said at the scene. Officials said the suitcase contained an acetylene torch, similar to blowtorches used for welding. Photographs displayed to reporters at the scene showed a "WARNING--HYDROGEN" label on the torch, and what looked like coiled wires.

Officials from Washington Gas Light Co. reported a similar suitcase missing yesterday, and Executive Assistant Police Chief Terrance W. Gainer said police were looking into the possibility that it was the suitcase left in the alley.

It was that possibility, Wade said, that got him jailed.

As units arrived on the scene, Wade was sitting on a bench in Franklin Square.

"One of the officers spotted me and shouted, 'There's the guy,' " Wade said. They then asked to interview him. "They said, 'You have no place to go, do you?' I said, 'Well, I'm homeless.' "

Within minutes, Wade was in a police mobile command unit parked on L Street, being questioned by agents from the police, the FBI, the ATF and the Secret Service. He was asked to give a written and signed statement of what he'd seen.

At 9:30 a.m., Wade was taken to the headquarters of the 1st Police District, he and police officials said. Wade said a detective asked him whether he had stolen the suitcase from Washington Gas Light and then called authorities to conceal the crime. Wade said his hands were shackled with a chain to the floor of an interrogation room.

Wade then was taken to central booking at the D.C. police headquarters at 300 Indiana Ave. NW. By 4 p.m., he was facing a judge in D.C. Superior Court, after a computer check turned up two outstanding warrants from 1997.

When Wade told the judge that the only reason the police found him was that he had notified authorities of a possible bomb, the judge thanked him, dismissed one of the warrants and freed Wade, giving him 60 days to pay $50 for the second warrant.

Gainer said D.C. police had no choice but to lock Wade up once a computer check turned up the outstanding warrants.

"I think he was treated professionally," Gainer said last night. "Given the nature of the circumstances we're dealing with, we owed it to the District at large to find out what information he knew and when he knew it and how he knew it."

Gainer and Ramsey thanked Wade on the sidewalk outside One Judiciary Square, "where he was regaling passersby with his exploits," Gainer said. Ramsey also wrote to businesses in the area, apologizing for the inconvenience caused by the investigation into the suspicious suitcase.

Gainer called back a reporter last night to say: "We don't want to discourage people who have minor criminal problems from helping the police. In this man's particular case, because there were warrants issued, we weren't in a position to give him amnesty."

Wade, who checked in last night at So Others Might Eat, a shelter where he often sleeps, said the experience left him angry.

"The next time, it could be a bomb in the making or a terrorist, I won't be the one reporting" it, Wade said.

CAPTION: People wait at 14th and K streets NW, outside an area that was cordoned off when a suspicious suitcase was found.

CAPTION: After alerting police to a suspicious package in an alley next to the Crowne Plaza Hotel, Mark Wade, a homeless man, ended up being detained for hours on an outstanding warrant for aggressive panhandling. No explosive device was found.