South Carolina authorities charged three persons yesterday in the shooting death of a Northern Virginia real estate developer whose body was found wrapped in a bedspread and bound with wire in the back of his vacation camper alongside Interstate-95 last month.

Charged with one count of murder each in the Sept. 27 slaying of C. Daniel Swansen are Richard C. Johnson, 22, of Morehead City, N.C.; Connie Hess, 17, of Omaha, and Curtis Harbert, 20, of Moorefield, W.Va., said Hugh Munn of the State Law Enforcement Division.

The three, described by police as hitchhikers picked up by the victim, are currently being held without bond in the death of a South Carolina highway patrolman, whose bullet-riddled body was found lying in roadside grass near Swansen's camper in Hardeeville, S.C., on Sept. 27, according to police.

South Carolina officials have indicated that they will seek the death penalty against Johnson, who authorities say wielded the weapon against Trooper Bruce K. Smalls, according to Johnson's attorney, Darrell Thomas Johnson Jr.

Authorities said yesterday they believe that Swansen, 52, a widely known Fairfax County developer, was shot once in the back of the head with a .357 Magnum pistol while sleeping in his 33-foot Holiday Rambler camper.

One of the complications of the Swansen case was determining when and in what jurisdiction he was killed, authorities said. Based on statements from the three suspects and a report from a trooper who reported seeing the camper during the early morning hours of Sept. 27, they believe that Swansen was killed while the vehicle was parked in the breakdown lane of I-95 south, about six miles north of Manning, S.C., said Ronald Stewart of the Clarendon County Sheriff's Department.

Swansen's body was not found until seven hours later, at 9:30 a.m., when police in Hardeeville, near the Georgia border, responded to a report that Trooper Smalls had been shot after stopping a camper.

Darrell Johnson, Richard Johnson's lawyer, said yesterday that his client told him that Swansen picked him up in a Datsun sports car while he was thumbing rides in Atlantic Beach, N.C., on Sept. 23.

The lawyer said his client maintains that the Swansen killing was precipitated by an argument over car keys and that the victim may have just awakened from a nap at the time of the shooting.

Johnson was arrested walking along I-95 about two miles north of the Hardeeville scene, and Hess and Harbert emerged from a clump of brush in the highway median strip and were taken into custody, police have said.

Gerald Kelly, the public defender representing Hess and Harbert in the Smalls case, said yesterday his clients hitched a ride to a nearby truck weighing station, where they reported the Smalls killing before returning to the scene.

Authorities say the trial in the death of Smalls may be held in mid-November in Jasper County, S.C. The Swansen case probably will be tried no earlier than January in neighboring Clarendon County, officials said.

Swansen, who was married and a father of three, has been described by friends and officials as a successful businessman who seemed shattered by the accidental death of a son several years ago, and whose subsequent behavior had grown increasingly erratic.