Father-of-eight Anthony Sargeant, 33, was shot on 25 August 2018 on the street outside his mother's home on Rickman Drive, Lee Bank in Birmingham.
Brothers Michael and Connor Goodwin, 27 and 28, along with Keenan Anderson, 26, and Leon Riley, 22, were given lengthy jail terms on Friday.
A row broke out at the end of the court hearing in the packed public gallery. The shouting and scuffling then continued outside the court, on the stairs and outside the building.
Murder trial defendants Connor, 27, and Michael Goodwin, 28, Leon Riley, 21, and Keenan Anderson, 25, Albert Road, Handsworth, were all sentenced to life.
A spokesman for West Midlands Police told the Express & Star: "We arrested two men, aged 20 and 18, on suspicion of assault following a disorder at Birmingham Crown Court on Friday."
Connor Goodwin, 27, the oldest of the gang, was given a minimum term of 32 years; Michael Goodwin, 26, will have to serve a minimum of 28 years; Riley 28 years and Anderson 32 years.
The Goodwins, of Wallace Road, Oldbury, Leon Riley, of Bridgelands Way, Perry Barr and Keenan Anderson, Albert Road, Handsworth and Dante Mullings, who was murdered in 2019, drove in convoy from Ladywood to Lea Bank and shot their victim outside his mother's house.
The sister of father-of-eight Anthony Sargeant gave an emotional speech about the loss of her older brother before sentencing.
She said: "On the day his heart stopped beating nothing has been the same. He was snatched away from us.
"Anthony never got to see his youngest child turn one. He was a devoted father who played an active role. He always pushed us to do our best. He was the backbone of our family. The void he has left is huge."