A veteran detective with the U.S. Marshals Service who is charged with killing his wife in their Loudoun County home tried to overdose on medication and waited nearly two days before he called authorities to report her death, court papers and a law enforcement source said yesterday.

John W. Ludwig, 51, a 17-year veteran of the Marshals Service, was charged Wednesday with first-degree murder in the slaying of his wife, Karen M. Ludwig, 38, after police found her body in an upstairs bedroom of the couple's Ashburn home.

According to an affidavit for a search warrant, Ludwig called 911 at 8:38 a.m. Wednesday and said: "I just shot my wife. . . . She's dead." When a sheriff's deputy arrived minutes later at the couple's home in the 42800 block of Hollywood Park Place, Ludwig identified himself and said his wife was upstairs, the affidavit states. There, the deputy found Karen Ludwig on the floor and a firearm at the foot of a bed, the document states.

In an interview later, Ludwig, whose birthday was Tuesday, provided investigators with an account of the events that led to the slaying, authorities said.

The affidavit also states that Loudoun emergency dispatchers received a call at 9:08 a.m. Wednesday from John Ludwig's mother's employer, who reported that Ludwig had called to tell his mother he "shot his wife and he had attempted to overdose."

Investigators who searched the house Wednesday afternoon found "remnants of heavy drinking" and multiple medications that appeared to have been "consumed in large quantities," said James P. Fisher, Loudoun's deputy commonwealth's attorney.

He declined to offer a possible motive for the slaying.

"The only real speculation is some type of very determined and deliberative rage on his part," Fisher said. "That's sort of what things indicate at this point."

Ludwig was arraigned yesterday morning and will appear in court again Monday to provide the name of his attorney, if he has retained one, or to ask for a public defender, Fisher said.

In addition to the murder charge, Ludwig probably will be charged with use of a firearm in the commission of a murder, Fisher said. Authorities said the revolver used did not belong to the Marshals Service. Ludwig is a criminal investigator with the agency, officials said.

Ludwig is being held without bond at the Loudoun County jail. Through jail officials, he declined to be interviewed yesterday.

The slaying was the fourth homicide in Loudoun this year and the second in Ashburn, a collection of tidy developments north of Dulles International Airport. According to public records, Ludwig had lived in the home since 1993. Neighbors said he and Karen Ludwig had married in recent years; it was John Ludwig's fourth marriage, Fisher said.

Neighbors interviewed Wednesday said Ludwig was friendly and a Harley-Davidson enthusiast who owned a handful of the motorcycles and rode each weekend with friends.

Staff researcher Bobbye Pratt contributed to this report.