NEW YORK, United States (AFP) — Prosecutors trying the case of Sean “Diddy” Combs on Monday began questioning witnesses to his alleged pattern of violence, including the music mogul’s ex-girlfriend’s one-time best friend.

Following nearly a week of gruelling testimony from Casandra Ventura, who was with Combs for more than a decade, Government attorneys are vying to build their broader racketeering charge that accuses Combs of heading a criminal enterprise that was involved in arson, kidnapping and bribery.

In addition to that federal count Combs, 55, also faces sex trafficking charges. If convicted, the one-time powerful figure in the music industry could land in prison for life.

Ventura, the 38-year-old singer known as Cassie, testified over four days that she was subjected to years of harrowing abuse and coercive, drug-fuelled sex marathons known as freak-offs.

Her one-time best friend Kerry Morgan, a 39-year-old personal assistant who met Ventura when they were teenagers in the modelling industry, described the singer’s relationship with Combs as physically and psychologically abusive.

“She lost her confidence big time,” Morgan told jurors Monday. “She lost her spark. She was not the same Cassie.”

During one violent outburst in Los Angeles, Morgan said she urged one of Combs’ security guards to “do something” as the rapper and producer struck Ventura — he didn’t.

Morgan said aside from herself, most people in Ventura’s circle were Combs’ employees or associates, and that Ventura seemed to feel better about her relationship with Combs the more time she spent with them.

“You could tell they were convincing her it was okay,” Morgan said.

Persuading jurors that a web of employees propped up Combs’ alleged crimes is key to the prosecution’s case.

Morgan was with Ventura in the hours following the now-infamous 2016 incident at the Los Angeles-area InterContinental Hotel.

Security footage that jurors have now seen multiple times shows Combs on that day beating and dragging Ventura, who testified she was trying to flee a freak-off.

In the aftermath Morgan, who was staying at Ventura’s home, said Combs arrived there and began banging at the front door with a hammer.

Ventura seemed “numb”, Morgan said: “I don’t think she cared if he came in and killed her.”

Morgan said at times she encouraged Ventura to leave Combs, or call the police.

Ventura would respond that “she couldn’t”, Morgan testified, “because of her job, her car, her apartment. Combs controlled everything”.

“She would have lost all of her livelihood.”

Morgan said Combs struck her as well, an incident that prompted her to end her contact with both him and Ventura.

Morgan told the court Combs was looking for Ventura one day and “boomeranged” a wooden hanger that struck her in the head and caused a concussion.

She said it was a line-crossing moment and that she only saw Ventura one more time. Morgan said she signed a non-disclosure agreement in exchange for US$30,000.

Following Morgan’s testimony, the Government called to the stand David James, who was a personal assistant to Combs during the time he dated Ventura.

Monday began with an intense cross-examination of Dawn Richard, a singer who found fame in the girl group Danity Kane that came out of MTV’s reality show Making the Band, which Combs produced.

Richard has a pending civil suit against Combs alleging sexual assault and battery.

While Richard was a performer in the group Diddy — Dirty Money from 2009-2011, she said she witnessed Combs attempt to hit Ventura in the head with a skillet.

When Ventura curled up on the kitchen floor in fear, he punched and kicked her, Richard said.

Richard described two other similar fits of rage, including one time when Combs punched Ventura in the stomach at a Los Angeles restaurant.

Nicole Westmoreland, a lawyer for Combs, painstakingly scrutinised Richard’s version of events in a bid to cast her as unreliable, also painting her as money-hungry in light of her civil suit.

The defence attorney pointed out inconsistencies between the singer’s statements on the stand, in her own suit, and in records of meetings with government lawyers.

“You would agree with me that as time progresses your story changes,” Westmoreland asked.

Richard replied “yes” — but later explained under more questioning from prosecutors that she has long aimed to forget those years she described as “a hard time”.

“Every day it gets easier to remember,” she said.