The deadly shooting outside a wake in Brooklyn began as an altercation between two men who had a disagreement that dated back nearly two decades, police sources say.

The sources say that 40-year-old Sharieff Clayton, of the Bronx, got into an argument with Fritz Celestin while attending services for a mutual friend at the Emmanuel Church of God. They say Celestin left and returned with two other men, and that's when gunfire was exchanged.

Clayton was killed in the shooting, along with 44-year-old Ronald Murphy, of Brooklyn.

Investigators say Celestin was found in an SUV a few blocks away, bleeding with gunshot wounds to the stomach. He was rushed into surgery and remains hospitalized.

Meanwhile, the community gathered Tuesday for a candlelight vigil in memory of the lives lost. Loved ones say Murphy was a good man who lived a peaceful life. 

Clayton's family maintains that he was not affiliated with any of the victims or shooters. They say he was a beloved father, husband, motivational speaker and author, who was a positive role model in the community. He was a caseworker working with juveniles, a family spokesperson said.

A representative from Emmanuel Church says they were given the OK to resume activities in the building. They also say that the incident has no connection to the church.

Police are reviewing surveillance video in the area as part of an ongoing investigation, but so far no suspects have been identified. No arrests have been made.

Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS.