Twice, 19-year-old Joshua Cooke dialed 911. Twice, he calmly spelled out his address in Oakton. And twice he told Fairfax County call-takers, "I just killed both of my parents."

Fairfax Commonwealth's Attorney Robert F. Horan Jr. played the tapes of Cooke's calls to police during a preliminary hearing yesterday in Fairfax Juvenile and Domestic Relations Court. Cooke is charged with two counts of first-degree murder in the Feb. 17 deaths of his parents, Paul C. Cooke, 51, and Margaret Ruffin Cooke, 56. Judge Jane P. Delbridge, finding that there was probable cause to believe Joshua Cooke had committed the crimes, sent the case to a grand jury.

Fairfax officers needed more than 10 minutes to reach Cooke's home in the 10500 block of Adel Road, about a half-mile west of Hunter Mill Road, because of the huge snowstorm that had blanketed the Washington area that week. When they arrived, Cooke was waiting at the end of his driveway, speaking on the phone to dispatchers and drinking a can of soda, according to court records.

Officer Eric Leeds testified that when he entered the Cookes' home and walked through the dining room, he saw a shotgun leaning against a piece of furniture and 15 to 20 live rounds lying nearby. When he went to the basement, he saw the bodies of Paul and Margaret Cooke. A police search warrant says investigators removed eight spent shell casings from the house.

Paul Cooke is the son of Paul P. Cooke, the former president of D.C. Teachers College, now the University of the District of Columbia. Several Cooke family members watched the hearing yesterday, but Joshua Cooke did not look at them.

Amanda J. Russell, a Fairfax 911 operator, testified that she received Cooke's first call at 7:22 p.m. Horan played the tape.

"Yeah, I'm at 10504 Adel Road. You've got to get over here," the caller said. Russell asked him to repeat the address, and he did, spelling out "Adel."

Russell asked why he needed police. "I just shot my parents," the caller said. "I just blew 'em away with a shotgun. A 12-gauge shotgun."

"Why?" Russell asked, but the caller hung up.

Minutes later, Capt. Keith H. Johnson of the Fairfax fire department took a second call. "Yeah, this is Josh Cooke again," the caller stated. "I just called a few minutes ago and nobody's here yet."

Johnson asked why he had called before. "I just killed both of my parents." The caller again provided the address and told Johnson that his parents were in the basement, shot by a shotgun.

"I know I'm 19," the caller said. "I know I'm going to get the . . . death penalty for this . . . . But that's the way it is."

The caller then told Johnson that he had left his weapon inside the house. "I will not be armed when they get here," the caller said. "I do not want to get shot down by police." After about a minute, the sound of police arriving and ordering the caller to the ground are captured on the tape.

Cooke is being held without bond in the Fairfax County jail. His attorney, John H. Partridge, did not present any evidence during the hearing and declined to comment afterward.

Cooke apparently bought a shotgun two days before the killing. Earlier this month, police obtained surveillance tapes from a Galyan's sporting goods store in the Fair Lakes area of Fairfax after finding a receipt for the gun in the Cookes' house.

An affidavit written by Fairfax homicide detective Robert Bond said the receipt showed that Joshua Cooke had purchased a shotgun, ammunition, a case and a cleaning kit Feb. 15.

Authorities said there is no waiting period for the purchase of a long gun, such as a rifle or shotgun, if the buyer passes a background check.

Fairfax prosecutors have not indicated whether they would seek the death penalty for Cooke. Authorities also have not stated what they believe to be the motive for the killings.

If the grand jury indicts Cooke, the case would move out of Juvenile and Domestic Relations Court to Circuit Court. Cases involving most family-on-family crimes start out in the domestic court.