$10,000 reward offered for information leading to capture of suspected killer who was accidentally released from Indianapolis jail

The US Marshals Service is offering $10,000 for those who come forward with information leading to the arrest of a suspect in a 2021 killing who was released from a detention center in Indianapolis last week due to a clerical mistake, officials said.

Kevin Mason, 28, was "mistakenly released" from an adult detention center in Marion County on September 13, two days after his arrest, "due to a faulty records review" by staff, according to the Marion County Sheriff's Office. A manhunt for Mason is underway, and the sheriff's office is asking for the public's help finding him.

It's unclear whether he's still in the county, sheriff's Col. James Martin said in a news conference Tuesday.

Mason was arrested in Indiana on September 11, having been sought on three Minnesota warrants, including one asking he be held on suspicion of murder in connection with a 2021 shooting in Minneapolis, the sheriff's office said. The other warrants relate to an alleged parole violation and firearms possession, Martin said.

He was released after a Marion County sheriff's clerk thought she was correcting duplicate bookings for the inmate and removed two holds in his file, Martin said. The next day, a clerk in Minnesota lifted the final hold in Mason's file and did not catch the error that happened the day before, according to the colonel.

Two inmate records clerks involved in Martin's release have been fired, and an internal investigation is being conducted, according to Martin.

"This was an error - this should not have happened. Mason should not have been released from our custody," Martin said.

Officials discovered the error "shortly after" Mason's release and a "round-the-clock" manhunt has been underway ever since, Martin said.

A woman described as being Mason's girlfriend was arrested Wednesday afternoon on suspicion of assisting a criminal, Marion County Sheriff Kerry Forestal said at a Wednesday news conference.

Mason had called her for a ride when he was released from custody, and "we've been tracking that girlfriend since," Forestal said. Officers tried to speak with her but "she has not cooperated," the sheriff said.

The woman still was being held early Thursday with no bond set, jail records showed. No attorney or court date was listed in the records.

The search for Mason comes on the heels of a massive manhunt that captured national attention in Pennsylvania. Convicted killer Danilo Cavalcante escaped from a Pennsylvania county jail by "crab-walking" up to the roof on August 31 and managed to evade hundreds of officers searching for him for nearly two weeks before he was recaptured in the woods.

The US Marshals Service, which was involved in the search for Cavalcante, is now overseeing the investigation, the sheriff's office said in a Friday update. The sheriff's office said it had made contact with law enforcement agencies in areas where Mason is believed to have connections.

"As a former U.S. Marshal, I have a personal understanding of the far-reaching tools our federal partners have," said Marion County Sheriff Kerry Forestal. "With 56 regional task forces and their capture of nearly 76,000 fugitives in 2022, I am fully confident they will locate Kevin Mason and bring him into custody."

The sheriff's office waited six days to alert the public of Mason's accidental release because it wanted to maintain a "tactical advantage," Martin told reporters.

"We have used this time as the quietness of the situation to not further run him underground and send him running further than what we wanted him to," Martin said.

Mason has "local ties to Indianapolis" and had been in the area since the killing he is accused of in Minnesota, Martin said.

Investigators are concerned Mason may have left the area since leaving custody, and that someone may be helping him, the colonel said.

"He has obviously evaded law enforcement since 2021. We believe that he is pretty good at what he does," Martin said.

The sheriff's office asked the public to come forward with any information on Mason's whereabouts.

Mason is described as weighing 205 pounds and standing about 5'9" tall, with a cross tattoo under his right eye and a tattoo reading "SUB" on his chest.

"We do not have any information that leads us to believe that the public is in any immediate danger at this time," Martin said, but told members of the public to "not approach Mr. Mason in any form or fashion."

CNN's Andy Rose and Samantha Beech contributed to this report.