He overheard Forman becoming aggressive towards Harooni when she joked about receiving a text from an ex.
The driver said he continuously hassled her, demanding her phone, and got increasingly angry as she didn't let him have it. "You're scaring me," Harooni reportedly told her boyfriend.
Sabrina Harooni was brutally beaten up to death. Photo / Supplied
Worried, the driver told authorities he drove up the street but returned with his windows down and could hear the two arguing. He waited until the yelling stopped and then drove off.
The nurse who performed CPR on Harooni said she could feel fluid in her lungs.
A search of Forman's house found a large clump of hair similar to Harooni's and a piece of carpet, pillowcase and fitted sheet with blood on them.
Forman reportedly told police three women had beaten up Harooni the night before.
Investigators searched two phones found in Forman's possession and found a photo, taken shortly before midnight, showing Harooni seemingly unconscious, lying on the grass outside the house.
They also found a video where the man filming it can be heard saying: "This is what a cheating liar gets. You hear me? Cheating f*****g liar."
