Five people have been accidentally released from the Denver downtown jail in 2014 alone, the most since the facility was opened in 2010, the Denver Post reported.
They were all taken back into custody, but one of the escapees was gone for more than two weeks.
The case is still under investigation, so the Denver Sheriff's Department said they can't release any specific details.
Interim Sheriff Elias Diggins said he has updated the inmate release system to try to limit the times when prisoners were released too early.
"We don't want to have any erroneous releases," Diggins said. "We want to be sure that anyone who is supposed to be in custody is in custody."
Releases can happen when names are mixed up, jailed people find a way to rig the release system, or officers miss warrants or holds from other jurisdictions.
Between Jan. 1 and Nov. 5, the Downtown Detention Center had five releases, according to data collected by the Denver Department of Public Safety. In the city's two jails, 30,777 people in total were let go, KJCT reported.
One person was out for 16 days before being apprehended. Two were nabbed in the same day they were let go, according to the department's findings.
It's believed that three of the five people were in jail on assault charges, city records state. Outstanding warrants were also issued for four of them. It's hard for corrections officers to say how many accidental releases are too many, especially if the jailed people are dangerous or commit other crimes while they are released.
Diggins couldn't say why there had been an increase in Denver, but it's not the worst compared to some of its neighbors in the west.
For example, the Salt Lake City County Jail, which is comparable to Denver's in size, had seven accidental releases this year.
The San Diego County Sheriff's Department, which is quite a bit larger than Denver, has reported four releases since just Nov. 12.
