It was a beautiful afternoon over Memorial Day weekend, and Mark Creasy was cycling along a popular bike and jogging path on Daingerfield Island in Alexandria. About 4 p.m., he was strangled, police said, and his body was found with his helmet still on.

U.S. Park Police were sorting through numerous tips yesterday to try to figure out who killed Creasy, 48. Police are focusing on whether there is a connection between Creasy's death and the arrest of a naked man who ran across the George Washington Memorial Parkway about a half-mile away, within an hour of the discovery of Creasy's body.

Alexandria police said the man ran across the parkway at Bashford Lane. When confronted by police, he threw a bottle at two officers, kicked others and tried to bite at least one officer. Alexandria police yesterday charged the man, Andre D. Suggs, 35, of Alexandria, with six counts of assaulting a police officer.

Sgt. Scott Fear, a Park Police spokesman, said, "Obviously, that is something our detectives are looking at closely, because it was an arrest in the area, in the same vicinity, during the same time period."

The body of Creasy, of Alexandria, was found about 4:45 p.m. Saturday on federal land near a National Park Service maintenance site between the parkway and the Potomac River. Fear said police have received nearly a dozen calls from possible witnesses, "a bunch of them with very good information," and are hoping to make a quick arrest.

Creasy's death was the second homicide in recent years on Daingerfield Island, a 109-acre strip of land that extends into the Potomac north of Old Town Alexandria and south of Reagan National Airport. In September 2001, Joaquim Diaz, 19, was stabbed repeatedly, his throat cut from end to end and his larynx removed. Two members of the violent Mara Salvatrucha street gang, or MS-13, were convicted in his death.

Last year, a homeless woman, Roslyn Whitehead, was stabbed to death along the parkway about eight miles north of Daingerfield Island. Her slaying remains unsolved.

Little could be learned about Creasy, who was described by neighbors as an avid cyclist in good physical condition. A distant cousin, Olin Creasy, said that Mark Creasy grew up in southwestern Virginia and that his death was announced Sunday at a family reunion near Roanoke.

Federal officials said Daingerfield Island and all nearby federal parkland are safe. Over the past 15 years, police said, no more than five homicides have occurred along the 23-mile stretch of the parkway and adjacent national parkland patrolled by the U.S. Park Police.

Fear emphasized that the three more recent slayings were isolated incidents. He added, however, that "we are always telling people to be vigilant, to look over their shoulders. We always tell people to run in pairs."

Bill Line, a spokesman for the National Park Service, said more than 7 million people get out of their cars each year along the parkway and visit nearby parkland, including Daingerfield Island. "We certainly believe that the George Washington Memorial Parkway and, more specifically, Daingerfield Island is a very safe area," he said.

Daingerfield Island, home of the Washington Sailing Marina and Potowmack Landing Restaurant, is used for everything from biking and jogging to sailing, fishing and soccer.

People interviewed there yesterday were surprised to hear about the homicide but said it would not stop them from visiting.

"I've never felt uncomfortable or in any danger," Vincent Bates of the District said as he changed out of his work clothes in a parking lot near a vast open field. "It's a nice place to sit and read or walk. It's always quiet."