At about 4 a.m., police responded to a call about several shots fired inside and outside Manny's Blue Room in the 2900 block of South Claire Boulevard.
Midlothian police said one of their officers -- who was called to assist Robbins police -- fatally shot bouncer Jemel Roberson after entering the bar and seeing him holding a gun.
Circumstances surrounding the shooting of the bouncer or the initial gunfire were immediately unclear. At least four people were shot including Roberson.
Midlothian police Chief Dan Delaney said: "Upon arrival officers learned there were several gunshot victims inside the bar. A Midlothian Officer encountered a subject with a gun and was involved in an Officer involved shooting. The subject the Officer shot was later pronounced deceased at an area hospital"
Roberson was an organist at New Spiritual Light Baptist Church in Chicago.
"How in the world does the security guard get shot by police?" asked the church's pastor, Walter Turner. "A young man that was literally doing his job and now he's gone."
Those who knew Roberson described him as a man of God who shared his musical talents at several churches around the city, last rehearsing at this South Shore church on Thursday.
"He said, 'Ma and pops, I'll see you all Sunday and I jokingly said, 'You better make sure you're on time for morning worship. He said, 'I'll be there pops. I'll see you then,'" Turner said.
Because this is a police-involved shooting, the Illinois State Police is now in charge of that part of the investigation. While the Cook County Sheriff's office is now assisting with the overall criminal investigation.