R&B singer Cassie testified Tuesday against Sean "Diddy" Combs as part of the latter's sex trafficking trial in New York.

Casandra “Cassie” Ventura is expected to take the stand in her ex Sean “Diddy” Combs Manhattan sex-trafficking trial on Tuesday, with testimony that’s poised to be a tell-all accounting of his alleged pattern of abuse. Here’s what to know.

The federal sex trafficking case against Sean “Diddy” Combs began with disturbing and graphic testimony from a key witness. Daniel Phillip, a 41-year-old escort, testified that the music mogul paid him large sums to perform sexual acts with Diddy's ex-girlfriend, Cassie Ventura, while Diddy observed and gave directions.

Prosecutors in opening statements called Combs a cultural icon to the public – but alleged he 'committed crime after crime' in private.