Police are investigating the events that led up to a fatal stabbing Saturday in Beverly Hills.
Detectives say initial reports indicate there was a confrontation between two men near the intersection of Spalding Drive and Charleville Boulevard.
A witness who asked not to be identified tells NBC4 that the injured man police arrested allegedly tried assaulting a father with a little girl near that same intersection.
"He had a baby in his arm and being attacked by an assailant was clearly a situation that we couldn't just drive away from, so we pulled up right in front of them," said the witness, who intervened. "He was not present, he was having some kind of psychotic break, and so it was kind of scary."
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The witness says as soon as he pulled over his son jumped out to help the father and child – he then saw the man with a deep cut on his face turn his attention to his car and said he tried grabbing his dog.
"I reached back, grabbed her, and then was pulling her back, but he wouldn't let go, so I was pulling her, he was pulling her, and then I started punching him because I was yelling at him to get out of my car."
The witness says during this time his car slowly rolled into a yard on Spalding– and saw the injured man stumble away towards a nearby home. He added that he did not see how the fatal stabbing happened.
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The man with the stab wound was taken to a hospital where he later died, according to authorities.
Police have not released the identity of that man and say the other person involved in the confrontation is cooperating with investigators.