CALICO ROCK, Ark. (AP) — Officials scoured Arkansas’ rugged Ozark Mountains for a former police chief and convicted killer who escaped from prison over the weekend.

Grant Hardin, who briefly served as police chief for the small town of Gateway near the Arkansas-Missouri border, was serving a decades-long sentence for murder and rape.

Known as the “Devil in the Ozarks,” he escaped Sunday from the North Central Unit, a medium-security prison in Calico Rock.

Hardin’s escape happened days after 10 men fled a New Orleans jail by going through a hole behind a toilet. Eight of those fugitives have since been captured.

Here’s what to know about Hardin and his escape:

How did he escape?

Hardin escaped from the prison Sunday afternoon by impersonating a corrections officer “in dress and manner,” according to a court document. A prison officer opened a secure gate, allowing him to leave the facility.

The outfit was not a standard inmate or correctional uniform, said Rand Champion, a spokesperson for the Arkansas Department of Corrections. Officials are working to determine how he was either able to get the uniform or manufacture it himself.

Video surveillance shows Hardin escaped at about 2:55 p.m. on Sunday, Champion said. Officials announced his escape about two hours later.

But how he got out of the prison and escaped into a rural part of the state, as well as whether he had any help is still unclear.

Prison officials say they are investigating what led up to the escape “to help determine any assistance he may have had.”

Champion said the decision to house Hardin in a medium-security facility, which has a capacity of about 800 people, weighed the “needs of the different facilities and inmates” and “assessments” of his crimes.

Why was he in prison?

Hardin had been held at the Calico Rock prison since 2017 after pleading guilty to first-degree murder for fatally shooting James Appleton, 59.

Appleton, a Gateway water department employee, was shot in the head in 2017. Police found his body inside a car. Hardin was sentenced to 30 years in prison.

Hardin’s DNA was entered into the FBI’s Combined DNA Index System, and it matched the 1997 rape of a teacher at an elementary school in Rogers, north of Fayetteville. He was sentenced to 50 years in prison for that crime. He was a police officer in Eureka Springs at that time.

His short tenure as police chief

Hardin became police chief of Gateway, a town of about 450 people, in 2016.

Virtually overnight, people in the community described in the HBO documentary “Devil in the Ozarks” a dramatic shift.

“He was out chasing cars for no reason,” said Cheryl Tillman, one of Appleton’s sisters. “He was pulling guns on the citizens here in Gateway and then as time went on with him being the police chief things just started going down hill fast.”

The documentary revealed a crucial run-in between Hardin and Appleton in the Spring of 2016 in which Appleton stood up to Hardin about fixing a police car. A Benton county sheriff’s office lieutenant described several times when they got into each other’s faces and the dislike they both felt toward one another.

The city council gave him an ultimatum: resign or be fired. He stepped down four months after taking the position and nine months later, he killed Appleton.

The ‘Devil in the Ozarks’ documentary

Hardin was the focus of a popular 2023 HBO documentary, “Devil in the Ozarks,” that featured interviews with everyone from the victim of the 1997 rape and sisters of the murder victim to Hardin’s family.

It revealed key details about the bubbling resentment Hardin felt toward Appleton as well as revealing accounts of the moments right before and after the murder.

Then Gateway Mayor Andrew Tillman, who was Appleton’s brother-in-law, described being on the phone with him when he was shot, while local resident John Bray spoke about driving past Appleton’s car when the shooting happened. He was the first to find his body and identified Hardin as the shooter.

“I heard what I thought was someone had fired a rifle,” he said.

“I went back and I seen it looked like he had been shot,” he added, wiping away tears.

The documentary also includes security video of Hardin at a restaurant with his family just after the shooting and the police interrogation in which he tells law enforcement he has “the right to be silent” and opted not to give a statement.

The search for Hardin

Authorities are using canines, drones and helicopters to search the rugged northern Arkansas terrain, Champion said.

Although he did not reveal the exact areas of the search, he did say it has expanded as more time has elapsed since the escape.

Officials have faced challenges searching the areas as it’s very rocky and heavy rain has fallen in recent days.

The area around the prison is a rural part of the state, which can make Hardin’s escape more difficult. In a small community, there’s a higher chance someone will recognize him and alert the authorities, said Craig Caine, a retired inspector with the U.S. Marshals who has handled many cases involving escaped prisoners.

The Division of Correction and the Division of Community Correction are following leads with local, state and federal law enforcement agencies.