Feeling rejected and unloved by his parents, Alain Paul de Cock, 21, took a rifle from his bedroom closet and shot his mother and father in the head at their McLean home on a snowy Dec. 13 afternoon, according to statements police said de Cock made three days after the killings.

During a preliminary hearing in Fairfax Juvenile and Domestic Relations Court yesterday, Fairfax County police related details of de Cock's statements to investigators after the slayings of his Belgian father, Romain Paul de Cock, 52, a World Bank loan officer, and mother, Simone Irene de Cock, 50.

Judge Thomas A. Fortkort ordered de Cock bound over for a Jan. 18 grand jury session and possible indictment on two murder charges and two counts of using a firearm in the commission of a felony.

In the courtroom, de Cock slumped in a chair, his head buried in his hands, tears streaming down his face throughout the 35-minute hearing. He sat between his two attorneys with his ankles bound by leg chains, listening to police accounts of his statements concerning the murders.

"He felt like he was no longer wanted" by his parents, police investigator Bill Mullins said de Cock told him in the statements. In his testimony, Mullins then reconstructed details of police conversations with de Cock during their investigation.

Tension had been mounting between de Cock and his parents since his sister's long illness and death last year from cancer. Throughout the teen-aged daughter's illness, de Cock said he felt as though they had devoted all of their time to the daughter, that he had lost touch with them, Mullins said.

"When he tried to talk to them, they would give him $5 or $10 and tell him to go buy something to get him out of the way," Mullins said de Cock told police. And after his sister died, de Cock said his mother nagged him constantly about how he lacked motivation.

Mullins said de Cock told police the nagging had started again when de Cock returned to the family's two-story home in the affluent Langley Oaks subdivision after a trip to the Tysons Corner shopping center.

"His mother complained about him not working, laying around the house," Mullins said. "She said she wished his sister was back: She was a good kid, he was no good."

De Cock, suffering from a bad headache all day, had been popping aspirin tablets, Mullins said de Cock told police. He asked his mother to get him a sinus tablet from the bathroom upstairs. When she refused, he went upstairs, took his .22-caliber hunting rifle out of his bedroom closet, waited until his mother came through her bedroom door and shot her in the right eye, Mullins said de Cock told police.

Mullins said de Cock then apparently emptied his mother's jewelry box into a pillow case in an attempt to make "it look like a burglary." De Cock later told police he forgot where he put the jewelry-stuffed pillow case.

Within three minutes of the first shot, de Cock heard his father enter the front door of the house. From a position at the top of the stairs, de Cock shot his father in the back of the head, Mullins testified de Cock said.

He then went down to the basement and hid the rifle in a crawl space, left the house and drove to the Washington home of his girlfriend, a student at American University, Mullins testified.

Three days after the slayings de Cock began relating these details to police, Mullins said. De Cock had originally told police he found his father dead after returning to the house shortly after 11 p.m. Police said de Cock's alibi was verified and he was not considered a suspect in the shootings.

The turning point came, Mullins said, two days later when de Cock told police he had "lied" when he told them earlier that there was no gun in the house. He told them he owned a .22-caliber rifle hidden under a bath robe in his closet. Police found no gun in the closet, but after a midnight search of the house discovered the rifle in the basement crawl space.

"Then we began to have some doubts about his story," Mullins said.

De Cock's attorney, Daniel Grove, said during the hearing that de Cock was questioned intensively for two days before police told him his rights and asked him to sign a waiver agreeing to answer police questions. Grove said de Cock should have been told of his rights immediately because one officer told de Cock that he was a suspect in the case shortly after the bodies were discovered.

Mullins said de Cock was not considered a suspect for almost three days, at which point police informed him of his rights. After the hearing, de Cock was led back to the county jail, his eyes swollen and face red after crying. He is being held on $500,000 bond.