Cassidy has been found guilty of involuntary manslaughter and aggravated assault.
The rapper was found to have supplying guns to kill Desmond Hawkins behind his house in Philadelphia last April.
Cassidy - real name Barry Reese – was ordered to serve 11 and a half to 23 months behind bars by judge Cutler Greenspan.
However, Cassidy has been in custody since June and will therefore serve a shorter term.
As the BBC reports, four guns had been used to kill Hawkins in the alleyway behind Cassidy’s home that the rapper had been storing in his house.
Judge Greenspan told him: “You could be a leader in the community. All those guns - that's why Desmond is gone now, because of all those guns."
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