Police were called to a house on the 1100 block of West King Street early Sunday morning.
The family get-together began Saturday night and went well into the morning hours.
The suspect, 33-year old Ricardo Magana-Lemus, was playing cards with his brother-in-law. At about 1 a.m. Sunday, the brother-in-law wanted to end the game. But the suspect, who was losing, didn't want to stop, and apparently would not take no for an answer.
"Suspect goes to his car and retrieves a weapon, comes back and there's a confrontation amongst the family, and at one point the suspect fires the gun, and the female victim, who is the wife of the person that he had been playing cards with, was struck in the head," said San Bernardino Police Lt. Jarrod Burguan.
The victim, 29-year-old Isabel Romero, died in the hospital.
Magana-Lemus fled the scene with the handgun. He is thought to be driving a 1999 burgundy Ford Explorer, with California license plate #4HFR161.
Magana-Lemus does have ties to Mexico, but authorities say he could be anywhere.
"We don't know exactly where he is at this point," said Burguan. "We have reason to believe that he still may be in the area. So we are putting the word out locally, but we've also notified authorities down in the border region and such, that he's wanted, and the vehicle description as well."
Magana-Lemus does not have a criminal history in San Bernardino County., but he is now wanted for murder.
San Bernardino Police are looking for the public's help to find him.
"He is wanted, he is armed and dangerous. The handgun that he used is still outstanding, so if anybody has information, come forward and contact us, we'd appreciate it," said Burguan.
San Bernardino Police Dept.: (909) 384-5742