Taxstone is facing a second-degree murder charge for his role in a shootout during a 2017 T.I. show in Manhattan which killed Troy Ave bodyguard Ronald McPhatter.
His trial begins this week.
Troy Ave was initially charged in the incident, but he cut a deal with the Manhattan District Attorney's Office to avoid prosecution.
As part of that deal, he will testify against Taxstone, who is currently locked up on federal gun charges.
He won't be the only one. Malcolm Kinyon, a drug dealer and gun runner, will testify that Taxstone admitted to him that he killed McPhatter.
Kinyon is currently facing 42 years, but one would imagine he will get some kind of reduction for taking the stand.