Two people died, and two people have been hospitalized following a quadruple shooting in an Antioch neighborhood late Thursday night.

Shortly after 10:20 p.m., officers received multiple calls of shots being fired in the area of "D" Street and West 19th Street, in front of Paqueteria Castaneda Market. When police arrived, they found four victims suffering from gunshot wounds and provided aid to the victims.

Police said two victims, identified as a 34-year-old male and a 42-year-old male, died at the scene.

Family members identified the 34-year-old as Julio Castaneda, the owner of the market. He would have turned 35 in two weeks. 

The second victim was identified by family only as 42-year-old Tomas, a close friend of Castaneda. They did not release his last name.

The two other victims, only identified as a 36-year-old male and a 15-year-old male, were taken to local hospitals. As of early Friday, the 36-year-old is in stable condition, while the 15-year-old is in critical condition.

"I'm feeling anger, sad. I just want justice," said Ismael Quintero, Castaneda's brother-in-law. "I'm just looking for answers, like, why this has happened, why?"

Quintero described Castaneda as a devoted family man. 

"He was a good, loving person," he said. "He loved his daughters; he loved the girls. He loved my sister to death."

Family members told reporters that several people were sitting outside the market and restaurant when someone opened fire.

A nearby resident told CBS News Bay Area, "I heard like, at least four or five gunshots. When I got closer to the area, I heard people screaming."

Longtime customer Coralia Ramos said Castaneda treated everyone who came into his store with kindness. 

"He treated customers like family," she said. "It's very sad. It hurts because you're not expecting it."

Quintero said his brother-in-law leaves behind four daughters and his longtime partner. 

"He had little girls. [The killer] left them without a father. I just want justice for my family," he said.

Quintero said Tomas also leaves behind a young daughter.

Police are investigating what led to the quadruple shooting but have not identified a motive. No arrests have been made. Authorities are urging anyone with information to come forward.

The Antioch Police Department's Investigation Bureau, consisting of crime scene investigators and the Violent Crimes Unit, is investigating.

Antioch police said the killings were the fourth and fifth homicides of the year for the city.

Anyone with information about the shooting is asked to contact Detective John Cox at 925-481-8147 or jcox@antiochca.gov.