Two 12-year-old boys accused of slaying a 7-year-old in order to get his bike had their case switched from Prince George's County to the federal district court here today. The change presents a new set of problems for authorities, including finding a place to detain the youths before their trial.

The 12-year-olds, who are not named in this story because they are minors, are accused of luring Carl Arthur of Livingston Road SE, from a playground to the Oxon Hill Childrens Farm last Easter. According to U.S. Park Police, the boys attempted to steal Carl's bike and they hit him in the head with a bat before pushing him into the Potomac River.

Police allege that the older boys threw rocks at the child until he backed up into deeper water and drowned.

Prince George's Assistant State's Attorney Hollis Wiseman, who said she had several discussions with federal prosecutors about the case, explained that she had state murder charges against the boys dismissed today after she determined that state courts do not have jurisdiction over the Childrens Farm, which is on federal property. Federal prosecutors, in a closed hearing in Baltimore, then charged the boys with attempted robbery, robbery, assault with a deadly weapon and second-degree murder.

This morning the boys' attorneys, Elvira White and Linda Spevack, arrived at the courthouse in Upper Marlboro expecting a hearing to drop the state's charges against the boys. What they saw instead were two federal marshals leading the small boys, in handcuffs and chains, out of the courthouse to their hearing here.

According to federal prosecutor Herbert Better, if the boys are found guilty their maximum penalty would be detention until they turn 21. Better said juvenile cases were rare in his office and said he was unaware of any federal juvenile detention centers in the area. Better would not comment on any specifics of the case.

Since the April 7 incident, the boys -- one from Southeast Washington, the other from Northeast -- have been housed in separate Maryland juvenile facilities. However, after today's hearing, the boys were transferred to a state-run facility in Northern Virginia, their lawyers said. It was unclear why the Virginia facility was chosen.

The defense attorneys said they were particularly concerned about where the boys will be held, because both are upset about being in a detention center. On two occasions last month, the Southeast boy tried to hang himself, according to White, his lawyer.

The Southeast boy's mother, who was at the hearing here today, explained that, "At first he wasn't aware that the little boy Carl Arthur had passed away . . . . When he found out, he took it real hard." The mother said her son is very confused, and she fears that he will try to kill himself again.

The defense attorneys were angry about the transfer of the case. "They've taken on the juvenile case, but they federal prosecutors don't know what to do with them the children ," Spevack said.

"What sort of program does the federal system have for a 12-year-old child? I know of none," White told reporters.

The defense lawyers said the boys were confused, frightened and eager to go home. But the attorneys did not ask that bond be set because they feared the boys might be taunted if they went back to their neighborhoods and that they would not have access to psychological counseling.