An Arlington judge dismissed murder charges against a District of Columbia man yesterday after a controversial investigation of a 1978 slaying.

Investigators employed a reputed clairvoyant and exhumed a body in an apparently futile search for evidence, officials said. Chief Arlington Circuit Court Judge William L. Winston dismissed the charges against Fred Tarpley Sr. after prosecutors acknowledged they had insufficient evidence to begin his trial.

Tarpley, 35, a computer programmer, was charged with fatally shooting John Francis Malone Jr., 45, a staff manager for the Chesapeake and Potomac Telephone Co., at his Arlington home May 21, 1978.Tarpley's trial was scheduled to start Monday.

Harry Toussaint Alekander, Tarpley's lawyer, said yesterday that Tarpley has sued Virginia, D.C. and Maryland officials in U.S. District Court, accusing them of violating his constitutional rights during the investigation. Tarpley has claimed false arrest and imprisonment and malicious prosecution, Alexander said.

"I know we've won," Alexander said after the murder charges were dismissed in Arlington. But he added: "Look what he's been through."

Tarpley was convicted in 1978 of impersonating an FBI agent and sentenced to three years' probation. Authorities said the conviction stemmed from the murder investigation.

At an Arlington court hearing, Alexander urged Judge Winston to dismiss the charges against Tarpley, arguing that the investigation had been unduly protrated. Prosecutor William A. Nunn III asked Winston, instead, to set aside the charges temporarily and allow the prosecution to bring charges again if further investigation warranted them. The judge accepted Alexander's arguments.

"There's been quite an intensive investigation, but we just didn't have the evidence," Nunn said later.

Officials declined to identify the clairvoyant who was hired to help find evidence during the investigation. They said the body of Tarpley's deceased mother was exhumed in a futile attempt to find a pistol allegedly used in the slaying. A murder weapon was never found, authorities said.

Malone was killed in the dining room of his home at 6015 N. 9th St., Arlington, authorities said. He was allegedly struck by pistol shots in his chest and one hand. Officials said his body was discovered two days after the killing.

Both counts on which Tarpley was indicted -- murder and use of a pistol in a murder -- were dismissed yesterday. Authorities said there were no witness to Malone's murder.