FERGUSON, Mo. — It will be hot in St. Louis on Monday morning, as temperatures approach 100 degrees and multitudes flock to a church on Dr. Martin Luther King Drive for the funeral of a young black man whose shooting death by a white police officer ignited unrest and renewed a familiar national conversation. There will be grieving relatives, resolute citizens, solemn politicians, several celebrities, and even emissaries from the White House.

Absent from the Friendly Temple Missionary Baptist Church, though, will be a tall, bald black man who now personifies this touchstone moment nearly as much as the 18-year-old being laid to rest. He is Capt. Ronald S. Johnson of the Missouri Highway Patrol, who, in many days of working to restore calm here in Ferguson, has redefined leadership in crisis: equal parts police official, preacher, mediator and neighbor, unafraid to convey his inner conflict, unafraid to cry.

Captain Johnson has already publicly expressed his condolences to the family of the dead man, Michael Brown, and he has thanked Mr. Brown for being a catalyst for change. But according to a spokesman for the highway patrol, the captain will be focusing Monday on continuing to provide security — though, out of respect, he will not be granting interviews to the news media.

“I just know that emotions are going to be high,” Captain Johnson said during an interview on Friday that was itself emotional. “But I think we have to respect those emotions. I think it would be wrong for me today to say, ‘Don’t let your emotions get high,’ because my emotions have been high in my lifetime when I’ve lost someone.”