D.C. jail inmates remain on lockdown more than two weeks after a rash of stabbings, prompting concern among advocates and family members who fear the prisoners will become violent and conditions unsanitary.

Three inmate-on-inmate stabbings, two of which were fatal, occurred during a 70-hour period that ended Dec. 14, according to correction officials. The killings were the first at the Southeast Washington facility in nearly five years. After the last incident, officials implemented a facility-wide inmate lockdown.

That lockdown has continued "to address the security concerns within the agency," said D.C. Corrections Department spokesman Darryl Madden.

"We have discovered some contraband, but before we release the lockdown status, we want to make sure we've gone through every aspect of the facility," Madden said of the 400,000-square-foot jail.

Under lockdown, inmates generally must remain in their cells except when they see visitors, are treated for medical problems or obtain psychological care, Madden said. Inmates had been allowed one hour of exercise a day starting Dec. 26; that was increased to two hours yesterday, he added.

About 75 percent of the cells hold two inmates, and the others are singles, Madden said. Televisions, radios and books are prohibited in cells, but inmates can have two days' worth of newspapers. They are allowed to shower at least once every 48 hours.

Family members and advocates said the lockdown has gone on too long and could create the unintended consequence of frustrating inmates to the point of violence.

Elias Henderson said he spoke with his grandson, an inmate who is incarcerated for violating parole, on Sunday. The grandson said that "tension was mounting," Henderson said, and that some inmates had started a fire in a cell.

"He's nervous, and he's mad, like all the rest of the inmates," Henderson said. "They feel like they're being mistreated because they are being punished for something they had no control over."

Advocates questioned whether crowding at the jail, which is designed to hold 2,424 and whose population was 2,305 yesterday, has convinced officials that the only safe way to operate the facility is to severely limit prisoners' movement.

"After the stabbings, they needed to do a search. They did the search. If they haven't completed it yet, I don't understand why. That's a very long time," said J. Patrick Hickey, a lawyer who has worked on D.C. jail cases for 30 years. "It is very crowded, but that does not justify a permanent lockdown. If they think the only way to manage a jail with 2,400 inmates is to have a permanent lockdown, they've got real problems there."

Madden acknowledged that the length of the lockdown is unusual. However, he said the jail had not had any killings in many years, and "given that, the length of this lockdown thus far is not disproportionate."

Madden added: "I will also say this: Managing an inmate population is very difficult during the holiday. "People miss home. . . . That's not to say under these circumstances you immediately lock people down, but given the rash of occurrences going into the holidays, we needed to make sure we took the most appropriate action."

D.C. Council member Sharon Ambrose (D-Ward 6), a member of the Judiciary Committee, said she was disturbed by the indefinite lockdown.

"You can't run a jail like that," she said. "That only creates another dangerous situation."

Ambrose and Kathy Patterson (D-Ward 3) have been working on legislation to limit the population at the jail. A court-ordered population cap of 1,674 was lifted in June after 17 years.

"Assuming the reason they went into the [long] lockdown was because of the overcrowding, this is not a good fix," Ambrose said. "Let's seriously deal with alternatives."