Forty-two inmates who reported to the D.C. Jail on Friday night to spend the weekend in one of the city's prison facilities sat in buses outside the jail for as long as 10 hours and were not transported to Lorton Reformatory until 4:12 a.m. yesterday, causing attorneys and others to question whether the jail population may have exceeded its court-ordered ceiling.

"It's going to present the question of whether people inside the jail confines should be included in the jail count," said Steven Ney, chief staff council for the American Civil Liberties Union's National Prison Project.

"The District is again playing this game exceedingly close to the line," said Ney, who represents sentenced inmates at the jail. "Perhaps they have gone over it the cap again."

The jail's 4 a.m. count is the one reported to U.S. District Judge William B. Bryant to verify the city's compliance with the 1,694 population ceiling he set for the jail. Yesterday's 4 a.m. count was 1,682 inmates, not including about 40 prisoners in the bus outside waiting to be taken to Lorton Reformatory in southern Fairfax County.

City administrator Thomas Downs, when asked where those inmates showed up on the department's 4 a.m. master population sheet -- which includes counts from eight facilities at Lorton -- said, "If in order to satisfy the imposed cap we need to establish Mobile Annex I, we can do that."

Downs was referring to ACLU attorney Alvin J. Bronstein's comment that the buses amounted to "the new D.C. Jail annex on wheels."

Yesterday, Bronstein said that "the concern is the place the jail has to be run in a constitutional manner for those people. It doesn't really matter who is out on the bus."

Asked whether keeping inmates on buses for 10 hours -- instead of in prison facilities -- satisfies the city's responsibility to provide humane housing to inmates, Downs said, "I don't know. There's no easy answer to that question."

It was the fourth straight night that inmates were kept from entering the jail because their presence would have pushed the population above the 1,694-prisoner ceiling.

Downs said the weekend crisis was brought on by the "unanticipated" flood of 77 "weekenders" who were sentenced by judges to spend the weekend in prison.

All the weekenders were eventually sent to Lorton Reformatory's Occoquan I facility, but they first had to have time-consuming physical examinations in the jail's infirmary and be processed through the Receiving and Discharge Unit, which keeps the master records on inmates incarcerated by the Department of Corrections.

Because the jail's population was so high Friday night, the weekenders were not allowed inside the jail en masse because the cap would have been violated. Instead, they were kept outside in two buses -- one for processed weekenders and the other for those waiting to enter the jail -- and were admitted to the jail in small groups.

The first bus, with 35 weekenders and five other jail inmates being sent to Lorton, left the jail at 12:15 a.m., Downs said. He said the last weekender was taken into the jail for processing at 3:05 a.m.

Despite the fact that numerous inmates were not processed through the jail until yesterday morning, according to a source with access to the jail's main computer, all of the 77 weekenders were listed on the computer as having arrived on Friday, which, he said, "means they were in the custody of the D.C. Jail."

"How can you say on the one hand that they were in my custody and I am going to give them credit for their days, and then on the other hand say they were not in my custody and we did not go over the cap?" the source asked.

Friday night, as the latest crisis unfolded, Corrections Director James F. Palmer said that the buses were heated, inmates had been given blankets, and arrangements had been made "for them to use outside [toilet] facilities."

Downs said that the jail population ceiling was not violated for yesterday's 4 a.m. count because "the weekenders were being held outside the [jail's] main control fence to avoid the cap." He said, however, that the inmates were inside the jail's perimeter fence.

How could the inmates be in custody and receive credit for their time, yet not be in custody for the purpose of the population count? Downs said, "From a paper work standpoint, it may show" that the inmates had arrived at the jail, "but I'm not going to worry about whether they were in the jail's custody unless the judge tells us we need to be."