Young Thug turned the steps of the Fulton County Courthouse into a stage Sunday afternoon with a surprise anti-violence concert at the same location where he pleaded guilty in a sweeping gang case last year.

Crowds gathered quickly after the Atlanta rapper posted an open invite on social media to pull up at 4 P.M. for what turned out to be a brief but pointed performance. Williams arrived just after 5 P.M. and performed for roughly 15 minutes. Afterward, he greeted attendees, signed autographs and shook hands before heading back inside.

The concert came nearly a year after Williams entered guilty pleas in the YSL RICO case, where prosecutors accused him and others of running a violent gang called Young Slime Life. After spending over two years behind bars, Williams pleaded no contest to conspiracy and admitted guilt to drug and weapons charges. He received a 40-year sentence, with five years credited as time served and the remaining 15 years on probation.