New Delhi, May 28 -- A former longtime assistant of music mogul Sean "Diddy" Combs took the stand on Tuesday (May 27) in a federal trial, offering harrowing testimony of threats, kidnapping, and violent abuse linked to Combs's relationship with his ex-girlfriend Casandra "Cassie" Ventura.

Capricorn Clark, who worked her way up through Combs's business empire, told jurors that in December 2011, Combs appeared at her home in a jealous rage, armed with a gun after learning that Ventura was seeing rapper Kid Cudi, whose real name is Scott Mescudi.

"He said, 'We're going to kill Kid Cudi,'" Clark testified, describing how Combs forced her to leave with him at gunpoint.

Cudi had testified earlier that his car was set on fire in January 2012,...