As the investigation into Chris Brown’s alleged assault on his girlfriend Rihanna continues, more and more horrific details emerge regarding what led to the fight between the two last weekend.

While Rihanna hasn’t yet pressed any charges against her boyfriend following Saturday night’s incident when she was reportedly threatened, beaten and left unconscious in the car, the Los Angeles County district attorney’s office has asked the police to collect more evidence before it determines which if any charges to file against the R&B singer.

According to an E! Online report, Brown threatened to kill Rihanna, as she reportedly told the authorities who arrived at the scene, but he strangled her so hard she lost consciousness. When the two started fighting, the “Disturbia” singer reportedly snatched Brown’s keys and tossed them out the window. He tried looking for them but couldn’t find them, returned to the car and “put his hands around her neck yelling 'I'm going to kill you!'”

He then took off and left her in his silver Lamborghini to the side of a street in L.A.’s Hancock Park neighborhood. Cops who arrived to the scene were so worried about Rihanna when they found her in the car looking distraught and sporting a severely swollen eye and handprints on her hands, that they drove her directly to the hospital instead of waiting for the ambulance to get there first.

Sources quoted by People magazine claimed that Rihanna’s injuries, which were previously said to be “horrific,” include a black eye, “a swollen split lip and two red and purple contusions on either side of her forehead.”

The investigation is yet to answer important questions like how did Chris Brown leave the scene after the alleged physical altercation with Rihanna, since he left his car behind, and if he got help from anyone in fleeing the scene.

Since both parties chose to remain silent concerning the incident, there are obviously many rumors going around about what went down between Rihanna and Chris Brown. Several rumors suggested that the brutal attack supposedly started with a text message Brown got from another female.

“He got a booty call. He got a text. Rihanna saw it and she got upset. They started to argue. She got out of the car. He wanted her to get back in, so he grabbed her. She pulled away. That's when she's told people he hit her,” sources told New York Daily News.

Friends of the Barbados-born beauty came out claiming that this wasn’t the first time things between the couple got physical. Apparently, she showed visible bruises on her neck back in December when the two were going through a rough patch, one friend told Usmagazine.com.

Meanwhile, Brown's sister, Lytrell “Tootie” Bundy, spoke about her 19-year-old brother to Extra saying he was “doing good” and coping as to be expected during this difficult time.