His family Friday paid tribute in an emotional news conference Friday and new details are emerging about the man arrested for the crime, 30-year-old Robert Vega.
RELATED: Community in mourning after beloved off-duty officer shot in Vallejo home
According to family members the two had a good relationship. Vega spent a lot of time at the officer's Vallejo home. ABC7 News spoke to a neighbor who gave us some insight into what might have led to this murder.
Neighbor Anna Lisa Gonzales recalls Thursday's shooting. "Our doorbell started ringing off the hook and she was banging on the door," she said.
It was Sandra Vegas at Gonzales' door, the wife of murdered Richmond police Officer Gus Vegas. She told her neighbor Vega had shot and killed her husband.
WATCH VIDEO: East Bay community mourns fallen Officer Gus Vegas
Gonzales said Sandra told her that the suspect had been hearing voices lately and that "this is the devil."
Many are wondering how a seemingly good relationship between the 15-year police veteran and the father of his grandson ended so tragically. Police say there was an altercation involving the two men, Vegas' daughter Angel and the couple's 6-year-old son.
Media release: Robert Vega booking photo dated 2/11/16 reference Vallejo PD homicide case pic.twitter.com/sxKpOjdNx5— Solano Sheriff (@SolanoSheriff) February 12, 2016
From their church, the family forgave Vega and praised Officer Vegas' life.
"The life as a police officer that he devoted to protecting others and a life as a father that he ultimately sacrificed in protecting his family," said the victim's son, Joe Vegas.
Vega was at the family's Vallejo home regularly and even called Gus Vegas "Dad." Neighbors at Robert Vega's Fairfield apartment say he appeared to be stable.
WATCH VIDEO: Family of slain off-duty Richmond officer forgives suspected killer
"It seemed like he stayed busy and had himself under control. He's ex-military too, so..." said neighbor Charles Jenkins.
The family says Vega is an Army veteran who had been deployed to Iraq and he was recently working in construction.
If you would like to help the Vegas family, there are two options.
A GoFundMe account has been set to the help the Vegas family. For more information, click here.
Also, the Richmond Police Officers' Association has created an account at Mechanics Bank in Officer Vegas' memory. All donations will go towards helping the Vegas family.
Routing number: 121102036
Account number: 041305213
Richmond POA in memory of Gus Vegas
Click here for full coverage on the Richmond Officer Gus Vegas.
Horrific sadness for Sandra Vegas, wife of Officer Gus Vegas who is bravely here with family to honor her husband pic.twitter.com/NZg7WWYEi3— Melanie Woodrow (@MelanieWoodrow) February 12, 2016
The cries and sobs are heart wrenching. So much pain here to a family that gave so much. pic.twitter.com/UBzkYJecZf— Melanie Woodrow (@MelanieWoodrow) February 12, 2016
Sandra Vegas said of Gus, he was my protector. I was the one who got to hear his stories every night. pic.twitter.com/Tu5XdJf8UU— Melanie Woodrow (@MelanieWoodrow) February 13, 2016