A 17-year-old Stafford County youth accused of assisting in the beating and burning of a mentally disabled man can be tried as an adult on murder charges, a Prince William County judge ruled yesterday.

Benjamin Hugh Hammonds Jr., who will turn 18 on Aug. 10, faces charges of murder, robbery and abduction in connection with the killing of Joseph Scott Williams, 32, who was fatally beaten July 1. Police allege that Hammonds and Danita Yvonne Corbin, 28, beat Williams inside Corbin's Dale City town house, stole $5 from him, then doused him in gasoline and set him ablaze in a nearby wooded area.

At a preliminary hearing yesterday, Domestic and Juvenile Relations Court Judge Rossie D. Alston Jr. referred the case against Hammonds to a grand jury scheduled to convene Aug. 2. Corbin faces similar charges.

Police allege that Corbin and Hammonds attacked Williams after a brief argument at Corbin's residence. Hammonds had been staying at the town house for the previous three days, police said.

Williams was a frequent visitor to the town house, according to Corbin's relatives and neighbors. Williams's siblings said he was a friend of Corbin's and was trying to help her with financial problems. Corbin's aunt said Williams had been sending love letters to Corbin, one of which arrived the day after he was killed.

Two 14-year-old boys--Corbin's son and another youth--were present during the attack but do not face criminal charges, Prince William Commonwealth's Attorney Paul B. Ebert (D) said, adding that both boys are "material witnesses."

At yesterday's hearing, Prince William police Detective David Watson testified that in a statement to police, Hammonds admitted to kicking Williams in the face and on the head several times.

Hammonds's court-appointed attorney, William Baker, did not make any arguments on his client's behalf, limiting his comments to cross-examination of Watson. After the hearing, Baker declined to comment on the case.

According to Watson's testimony, Hammonds told police that Williams took a swing at Corbin during their argument but missed. "She then hit him, and he went down," Watson testified. "He then sprayed pepper spray at Ms. Corbin, and that really upset her. Ms. Corbin went off, she started hitting Joe Williams about the head with her fists. They dragged him down the stairs, he was reluctant to go, then they beat him . . . numerous times in the head."

Police officers then came to the front door of the town house with an unrelated arrest warrant for Corbin and took her away without realizing that Williams's body was in the basement, according to Watson's account of what Hammonds told police. Ebert said the warrant charged Corbin with unauthorized use of a vehicle, and she was released on bond a short time later.

While Corbin was gone, Hammonds "panicked" and moved Williams's body to a wooded area about 160 feet from the town house, Watson testified. When Corbin returned, she suggested that the two of them burn Williams's body, Watson said Hammonds told police.

Hammonds told police that he went inside the house after Corbin had lit the blaze and tried to go to sleep but couldn't because "he wasn't sure if Mr. Williams was alive when he was set on fire," Watson testified. An autopsy revealed that Williams died as a result of blunt force trauma, with multiple lacerations and burning as contributing factors.

In his questioning of Watson, Baker focused on Hammonds's statements to police about Corbin's alleged role in the crime.

Robert Horan III, who is representing Corbin, said yesterday that he is aware of Hammonds's statements to police implicating his client. "There is a different version to the story that will be heard when this case goes to trial," Horan said.