In a report issued by the District's chief financial officer, the Department of Corrections said that in the 2010 fiscal year, it released up to 15 inmates per month during a nine-hour window beginning at 10 p.m.
But during the first five months of the 2012 fiscal year, that number fell sharply, with the jail releasing a total of five inmates during that period.
The decline began not long after at-large D.C. Councilman Phil Mendelson introduced a measure that would impose strict requirements about how quickly and when the Department of Corrections must release inmates.
Under the proposal, jailers would be required to free inmates within five hours of a court ordering them released or by noon of their scheduled release date. The measure would also fine the Department of Corrections $1,000 every time it released a prisoner between 10 p.m. and 7 a.m.
"If an inmate is in jail because he or she is completing a sentence -- typically a misdemeanor sentence -- everybody knows when the inmate goes in when they are going to be released," Mendelson said. "For them not to be able to release that person before 10 p.m. on the release date is, in my view, inexcusable."
Phil Fornaci, the director of the D.C. Prisoners' Project, said jail officials have blamed complex procedures for delays.
"The logistical issue is the main thing: getting people from the courthouse to the jail, checking their records and then releasing them on time. One would not think that would take very long," Fornaci said.
Francis Campbell, a Ward 6 advisory neighborhood commissioner, said a measure to further reduce the number of overnight releases was comforting, but he also said the statistics that showed any inmates were being released overnight were a surprise.
"We were all under the impression that no prisoners were being released at that time," Campbell said. "As minimal as it is, it is still an issue."
The Department of Corrections didn't respond to repeated requests for comment.