A woman testified on Wednesday in Sean Combs’s federal trial that he had held her over the balcony of a 17th-floor apartment and that she had once seen the music mogul burst into the home of Casandra Ventura, his former girlfriend, and throw a knife at her.

The woman, Bryana Bongolan, was a friend of Ms. Ventura — better known as the singer Cassie — and described a series of violent and threatening interactions with him.

Though Ms. Bongolan, a designer, had met and befriended Ms. Ventura around 2013 or 2014, when Ms. Ventura became associated with her fashion company, she said she hesitated to meet Mr. Combs. She had seen Ms. Ventura unsettled while on the phone with him, she said, and had seen Ms. Ventura with a black eye.

Once, near a photo shoot outside his home in the Los Angeles area, Ms. Bongolan said Mr. Combs accosted her. “He came up really close to my face,” she testified, “and said something along the lines of, like, ‘I’m the devil and I could kill you.’”

The witness also testified about another allegedly intense incident with Combs. She said she was at the beach with Ventura Fine and a photographer friend doing an impromptu photoshoot when Combs “came really close to my face and said, ‘I’m the devil, and I could kill you.'”

Bongolan, who said she was likely using cocaine at the time, described being “terrified.” She added that she wasn’t sure why Combs said that to her – or what prompted his alleged rage.

Bongolan recalled one shopping trip in early 2016 with Ventura Fine where she showed her friend her phone. Combs had allegedly sent “a list of places” where the women had been that day – but they hadn’t told him anywhere they were going on their shopping trip, Bongolan said, recalling her shock.

The designer also told jurors she saw Ventura Fine with a black eye on FaceTime before her movie premiere for “The Perfect Match” in 2016. While they spoke on video, Bongolan recalled that the friends quietly looked at each other, and she told Ventura Fine she was sorry.  

Bongolan recalled many instances where Combs would allegedly bang on the door of Ventura Fine’s apartment, often in the middle of the night. She said Ventura Fine sometimes seemed surprised, but at other times his aggressive arrivals seemed normal to her.

The witness remembered one night when she was sleeping and was awoken by Combs banging on the door. “He threw (a) knife in Cassie’s direction,” she alleged, telling the court that Ventura Fine later threw a knife back but didn’t hit him.

Cassie’s friend says they would do drugs weekly

Bongolan said she and Ventura Fine mostly spent time together at the singer’s apartment, where they would work on clothing designs, talk and use drugs. Bongolan said they did “a lot of marijuana” as well as some cocaine and ketamine. 

The designer alleged that Combs provided the her with drugs on three to four occasions, including ecstasy, cocaine, ketamine and GHB. Bongolan said she did drugs weekly with Ventura Fine, and she would often get drugs for the singer including oxycodone.

She said there were periods when she and Ventura Fine would try to get sober. “We wanted to do better,” Bongolan said. But those periods didn’t last. “It’s hard to get sober when there’s a lot of drugs around,” she said on the stand.

New footage shows Diddy throwing a vase toward Cassie’s head

Frank Piazza, a forensic video expert, walked the jury through a compilation video that he made, which showed the much-discussed 2016 hotel footage of Combs attacking Ventura Fine. However, the compilation also included a reflection in a mirrored wall showing Combs throwing a vase toward Ventura Fine’s head.