LAPD alleges 29-year-old Eric Holder opened fire on the rapper and two other men.
Witnesses said several people were stabbed at the gathering in South L.A.
The rapper was fatally shot Sunday in Los Angeles.
“Justice must be sought through legal means,” Supervisor Mark Ridley-Thomas said in a statement.
Two other people were wounded in the shooting on Slauson Avenue.
The soap opera star was found unresponsive at his home in Los Angeles.
“I personally took someone to the hospital myself,” Phora told ABC7.
“Black-ish” actor has “unequivocally” disputed the allegation.
“We have a crime report listing him as a suspect in a crime,” police say.
Award-winning singer is set to play a police officer investigating a cover-up.