Kenneth F. Schoen, a former probation officer who helped shift the nation’s criminal justice agenda for nonviolent offenders from fixed sentences in faraway prisons to flexible alternatives in their own communities, died on Sept. 1 in Duluth, Minn. He was 89.

The cause was bone marrow cancer, his daughter, Carrie Schoen, said.

In a period of rising crime Mr. Schoen became known in his field as the “father of community-based corrections” for promoting probation, halfway houses, drug rehabilitation and other options to incarceration.

He was Minnesota’s corrections commissioner from 1973 to 1978 and then director of the Edna McConnell Clark Foundation’s Justice Program, from 1979 to 1996, supervising the distribution of some $50 million in grants for prison reform and alternatives to confinement.

Mr. Schoen was in a position not only to propose programs — some of them unpopular — but also to implement and underwrite them and then demonstrate that they could be effective.

He also oversaw reforms in New York City’s detention system, including the notorious Rikers Island jail complex. Mayor Edward I. Koch recruited him as a consultant in 1978. In the 1990s, as a special master for the United States District Court in New York, he monitored the city’s compliance as it sought to improve conditions for inmates and staff, formulate regulations on solitary confinement, reduce violence, increase staffing, improve access to law libraries and develop due process procedures.

“We both wanted the same thing — a more just, less violent and efficient jail system,” Michael Jacobson, who was the city’s correction commissioner from 1995 through 1998 and is now executive director of the City University of New York’s Institute for State and Local Governance, wrote in an email, “and he balanced his role as a monitor and critic with a willingness to strategize and work with me on helping to get there.”

Michael H. Tonry, a criminologist, law school professor and the director of the University of Minnesota’s Institute on Crime and Public Policy, said that Mr. Schoen had been “a linchpin figure in efforts to change the U.S. justice system.” He added that as “an effective, liberal reformist” when he was commissioner in Minnesota, Mr. Schoen drafted legislation to help localities pay for drug rehabilitation and other services for offenders and former inmates.

Professor Tonry said that when Mr. Schoen directed the New York-based Clark Foundation program, it was the only significant philanthropy in the country that was funding criminal justice at the time. One recipient was the American Civil Liberties Union’s National Prison Project, which he described as “the backbone of the U.S. prisoners’ rights movement.”

While Mr. Schoen’s views were applauded by groups that favored prison reform and were concerned about the growing costs of incarceration, his work at the foundation drew criticism from the National Rifle Association, which warned in a report that his influence “casts a long shadow on more than a dozen state capitals and the White House itself.”

The N.R.A. countered by proposing that juvenile offenders be treated as adults, that states enact a victims’ “bill of rights,” that prisoner furloughs be abolished, that inmates be required to serve at least 85 percent of their sentences, and that a third felony conviction should prompt a mandatory life sentence.

Kenneth Frederick Schoen was born on April 21, 1932, in St. Paul, Minn., to Frederick H. Schoen, a railroad worker, and Helen (Geckler) Schoen, a homemaker.

Between earning a bachelor’s degree in sociology at the University of Minnesota and a master’s from the University of Colorado in Denver, he served in the Army as a psychiatric social worker in Germany.

In the 1960s, Mr. Schoen directed an experimental correctional program in Minnesota known as Probation Offender Rehabilitation and Training. He was named assistant commissioner for community corrections in 1972.

In 1996, he helped establish the Institute of Criminal Justice at the University of Minnesota Law School and directed it until 1999. He retired in 2000 and lived in Duluth. He married Concetta Infelise, who died in 2016. A son, David, died of cancer in 2004.