A Bay Area family was mourning Thursday night after a man was fatally stabbed in a Vallejo neighborhood that afternoon.

The stabbing happened as the victim, 27-year-old Christopher Armstrong, offered to help a neighbor and friend on the 900 block of El Dorado Street at 12:52 p.m.

Manuel Medrano, the victim’s friend, said Armstrong had arrived at his home to help him with some chores, accompanied by a homeless man who'd recently shown up in the neighborhood. 

“They actually walked down here together, and they started helping me clean the garage,” Medrano said.

But when Medrano went to the store the other man, 36-year-old James Alexander, allegedly attacked Armstrong, and stabbed him several times in the chest. He hadn't seemed violent before. 

“He was a little weird to us, but it kind of made us feel sorry for him,” Medrano said. “I don't know, I don't know what happened.”

The suspect ran after the stabbing, but he was spotted a few blocks away, and surrendered. Vallejo's Police Chief Josph Kreins credits the community for helping as witnesses to bring such a quick arrest.

A small memorial now sits in the neighborhood, an area not known for crime, for Armstrong.

Loved ones said they were stunned at the slaying of Armstrong, an avid baseball player, professional cook and community college student.

“He was free-spirited, funny --  the person I would go to talk to,” said Jessica Jaeger, the victim’s sister-in law.

Neighbors around the memorial Thursday night wondered if the suspect was an inmate who was considered  non-violent released from jail to save money.

“I'd inquired with the officers, and they think he's an early release out of Napa,” said Susan Anthony, a neighbor.  

This is the city’s third homicide of the year.

Kreins said he can't confirm yet if the suspect was on early release, but said Alexander does have a criminal history, including drug charges.

Two others homicides in February were shooting deaths, one gang related, the other one drug related.

“The real issue here is violent crime, it just seems violent crime is out of control, not just here in Vallejo, everywhere,” Kreins said.

Friends said Armstrong will be missed. 

"Strong-hearted, kind-hearted person, you know," Medrano said. "Like I said, my best friend."

Alexander will be booked on suspicion of murder, police said.

Anyone with information about the case has been asked to call Vallejo police Detective Raul Munoz or Detective Fabio Rodriguez at (707) 648-4524.