Man Arrested In D.C. Area's Arson Wave

But investigators' persistence in combing crime scenes generated evidence that yielded a DNA profile that could be used once they had identified a suspect.

At the site of an attempted arson in Northeast Washington in September 2003, investigators recovered the fire-setting device and a single human hair, the first step in developing the DNA evidence. They also recovered DNA from cloth -- the sock and the piece of pants -- found in two other devices left at fire scenes.

But the biggest break came Dec. 5, when Arlington County firefighters recovered Marine Corps dress pants and a Marine hat near a small deck fire in the 300 block of North Bryan Street.

Darlene Lloyd, left, Eddie Jones and Carolyn Jones gather in front of the home where their mother was killed.

Capt. Tom Polera of the Arlington Fire Department said the items were found near the scene. The blaze was never reported to the news media, Polera said, because of the little damage it caused and because of the evidence left behind.

ATF officials said they learned about the Arlington fire two days after it occurred. They said they were not convinced it was connected to the serial arsonist but decided to submit the pants to the agency's crime lab for tests.

It wasn't until April 1 that they got the results: DNA from the pants matched DNA recovered from the two earlier fires and attempted arson in Maryland and the District, authorities said.

Investigators then approached the Naval Criminal Investigative Service in hopes of identifying the owner of the clothing -- yielding the tip that led them to Sweatt.

Naval authorities told task force members that they had investigated several suspicious car fires set near the Marine Barracks at Eighth and I streets SE about 30 months ago, before the serial arsons began. They said they questioned Sweatt as a suspect in the car blazes.

Agents kept Sweatt under surveillance for several days, learning his routine. They questioned him April 19 and took a voluntary sample of his DNA. The Montgomery County police crime laboratory reported on Monday that technicians had matched Sweatt's DNA to the samples recovered from the three fires and one attempted arson, authorities said.

Authorities said Sweatt borrowed the Marine Corps pants from an acquaintance but it remains unclear why he left them at the scene of the Arlington fire.

Federal agents and other investigators yesterday searched Sweatt's apartment and his workplace, a KFC/Pizza Hut restaurant at New York Avenue and Bladensburg Road NE. They arrested him on Marlboro Pike after he left a regional meeting of managers at a KFC in District Heights.

Sweatt said little in court yesterday. His financial affidavit states that he makes $1,700 a month at the restaurant and has no other income.