(CBS NEWS) DAYTON, Ohio -- An Ohio pastor with deep roots in the Dayton community was shot and killed at his church Sunday, and police say they expect to charge his brother in the slaying on Monday.

CBS affiliate WHIO in Dayton reports that the victim, 70-year-old William Schooler, was a beloved community leader.

He was shot around 12:30 p.m. while in his office at St. Peter's Missionary Baptist Church, Dayton police said.

His brother, Daniel Gregory Schooler, 68, was arrested at the scene and taken to the Montgomery County jail. He faces a murder charge on Monday, said Sgt. Richard Blommel.

Police said they did not know Sunday what led to the shooting but said the pastor was the only intended victim.

Witnesses who were in the church said the choir was singing when the suspect walked up to the pastor and opened fire. Parishioners reported streaming out of the church after the shooting.

The pastor later died of his injuries.

Besides being pastor at the church, William Schooler was a past interim president of the Dayton school board and current president of the local Baptist ministers union.

He was a teacher in the Dayton school district in the 1970s and served as a principal in the Jefferson Township district for nearly two decades, according to the Dayton Daily News. He also held other positons with community organizations and local governments, including serving as a certified city of Dayton mediator.

"He had deep roots in the community," a friend, Ronnie Moreland, told the newspaper. "He was a beloved leader. It's hard to put into words what has happened."

Dayton City Commissioner Joey Williams told the Daily News he had discussed with Schooler ways to reduce violence in the community.

"For him to be a victim of violence is just extremely saddening," Williams said.