RICHMOND -- Homicide investigators arrested a 37-year-old woman for allegedly stabbing to death her 36-year-old boyfriend in a house in the affluent Point Richmond community early Tuesday.

The man's girlfriend called police about 4:30 a.m., reporting that the man was unresponsive and needed medical aid inside a home in the 500 block of Tewksbury Avenue, Richmond police spokeswoman Sgt. Nicole Abetkov said.

When fire crews and paramedics arrived, they performed CPR and other lifesaving measures, but the man was pronounced dead at the scene.

Then the rescuers noticed something else.

"The emergency responders noticed a stab wound, in the man's abdominal area, so they called police and we took over the investigation," Abetkov said.

The woman was being interviewed by homicide detectives at the police station Tuesday morning, Abetkov said, while investigators combed the crime scene for clues. By Tuesday afternoon, police announced they had arrested the woman on suspicion of homicide. She is being held at the Richmond Police Department pending charges.

The name of both the victim and the alleged killer were not released as of late Tuesday because the victim's next of kin had not yet been notified, Abetkov said. The victim was a white male, she said.

"The early indications are that it was a possible domestic violence situation involving alcohol," Abetkov said.

The homicide is Richmond's eighth so far this year and the first in Point Richmond, a sleepy coastal neighborhood with some of the city's most sought-after real estate. Violent crime is unusual there; Abetkov said it has been many years since police have investigated a homicide there. The area is within the Richmond city limits, but set apart by Interstate 580 and the Chevron refinery from the city's more crime-ridden neighborhoods.

The Contra Costa Times reported about a 2003 homicide in which a 22-year-old San Francisco man died at a house party in Point Richmond, but police were unable to confirm immediately if that was the most recent one there.

Investigators remained at the century-old, two-story house Tuesday afternoon.

"I heard nothing," said neighbor Roy Strassman, 68. "I go about with my eyes open but I don't fear here. I feel safe."

Joe Brubaker, who lives across the street, said a woman has lived in the home for years, and a man, possibly a boyfriend, moved in about a year ago. Brubaker, 42, said the woman keeps to herself.

"Other than the freeway, it's a pretty quiet place."

Richmond City Councilman Tom Butt, a Point Richmond resident since the 1970s, said, "Any homicide is very disturbing, whether in Point Richmond or anywhere else. But it is unusual here."

Staff writer Rick Hurd contributed to this report. Contact Robert Rogers at 510-262-2726. Follow him at Twitter.com/sfbaynewsrogers. Contact David DeBolt at 925-779-7166 and follow him at Twitter.com/daviddebolt