JENKINS, Ky. — A Kentucky judge who authorities said was fatally shot by a sheriff last week was remembered Sunday as a pioneer who fought opioid addiction and favored treatment over jail for low-level drug offenders.

Hundreds of mourners, including a procession of black-robed judges, filed into the Jenkins High School auditorium to pay their respects to District Judge Kevin R. Mullins, 54.

Letcher County Sheriff Shawn M. Stines is accused of shooting Mullins several times in the judge’s chambers Thursday afternoon. Stines has been charged with murder and is expected to make his first court appearance this week.

Authorities are investigating a motive. Kentucky State Police said the shooting appears to have followed an argument.

There was a heavy law enforcement presence at the service Sunday.

Several judges from across the state spoke at the funeral, sharing their personal experiences and billing Mullins as leader in the fights against opioid addiction and in support of the mental health needs of people going through the court system.

“His passion for people was his magic touch. He can’t begin to count the number of lives that he saved or improved,” said state Supreme Court Judge Debra Lambert, who sat on the state Judicial Commission on Mental Health alongside Mullins. “Our court family aches at his loss.”

Family members didn’t speak during the funeral. From her wheelchair, Patsy Holbrook Mullins hugged or shook the hands of mourners as they approached her son’s brown open casket, which was adorned with a bouquet of yellow flowers.

She told NBC News afterward that she was moved by the service and the community’s support.

“I’m very impressed by the outpouring of support and that the community is behind the mission that he wanted so much,” she said. “He wanted to bring a change to the opioid epidemic. That was his passion.”

District Judge J. Foster Cotthoff told the crowd of about 500 that Mullins “worked tirelessly” and that he was a state leader and innovator in opioid treatment.

“He saw the good in people even when they didn’t see it themselves,” Cotthoff said.

Mullins was a proponent of a rehabilitative approach for some offenders instead of jail time, according to a version of his obituary printed on the program for the service.

“From the outset as a judge, Kevin recognized that incarceration alone was insufficient in addressing the opioid epidemic in the Commonwealth,” it said.

Mullins “pioneered a local protocol focused on linking people to treatment services early in their involvement with the justice system, leading a transformative shift in how justice could support recovery,” the obituary said.

The protocol gained statewide recognition, it said.

Mullins also played a role in reshaping the Kentucky courts’ approach to behavioral health.

Matt Brown, president of Addiction Recovery Care in Kentucky, said Sunday that when low-level drug offenders entered Mullins’ courtroom, he would send them to drug rehab, not jail.

“He was an innovator,” Brown said. “He was way ahead of the curve.”

Mullins was born in 1970 in Pikeville, Kentucky. He began his career after he received a degree in political science from the University of Kentucky, and he later received a law degree from the University of Louisville, according to his obituary.

He was first appointed in 2009 to fill a judicial vacancy and served as a District Court judge for 14 years, the obituary said.

At the service, District Judge James Craft told a story about a trip he and Mullins took to New York City years ago.

Craft said Mullins, whom he described as a foodie, booked reservations at fancy restaurants for their entire trip but canceled on the last night because he wanted to try a cheeseburger.

“Kevin was a lot of things to a lot of people, but to me he was my friend,” Craft said.

In addition to his mother, Mullins is survived by his wife, Kimberly; his daughters, Mya and Ava; his sister; three nephews; and a niece.