Party organizers also hired an outside firm to help with security. That provided about 50 private guards on top of the hotel security detail, said police Sgt. Ed Everett.
Fliers for the event stated that about 5,000 people were expected to attend. Some people were turned away at the door.
Authorities said Baker was sitting outside the event, called NYE OC — which was hosted by Ones We Love Inc., a Newport Beach promotions company — when the confrontation occurred.
It was about 2 a.m. when people started to leave and Baker saw Robert Sickles, 27, of Mission Viejo, and his friends leave the event. Baker flicked a cigarette at them, prosecutors allege.
That's when Baker got up and confronted the group, pushed Sickles then pulled out a knife and slashed and stabbed him in the chest, killing him, according to police.
When Sickles' friend, 26-year-old Brian McTeigue of Mission Viejo, tried to intervene, he got stabbed in the back, police said.
During the fight someone in Sickles' group punched Baker in the face, police said. The fight was broken up, and Baker was held until police officers came.
Two Costa Mesa police officers were already at the hotel responding to various fight and disturbance calls, said Lt. Bryan Glass.
In the melee, Baker was stabbed in the back of his right leg, possibly by his own knife, officials said.
Sickles and McTeigue were taken to Western Medical Center in Santa Ana, where Sickles was pronounced dead. McTeigue has since been released and is recovering. Baker was taken to Mission Hospital in Mission Viejo.
Police said Baker and the other men didn't know each other before that night, and no one involved has gang affiliations. Hilton hotel representatives and event organizers did not return calls for comment Tuesday.
Baker faces 23 years to life in prison, if convicted.