Antioch police arrested a 34-year-old man on Sunday suspected of killing his partner and their 15-year-old son, according to an Antioch Police Department press release.
Officers were dispatched Sunday evening after 8 p.m. to do a welfare check at the 2100 block of Lemontree Way after a caller reported that they had not heard or seen their neighbor in several days.

When officers arrived at the scene, no one responded to the door, and through the window, a 15-year-old boy was spotted unresponsive on the floor.
Due to "concern for life" officers forced their way into the apartment. Once inside, officers discovered that the boy was dead, and after searching the rest of the residence, they found a 30-year-old woman also dead in a different room.
Both the woman and the boy had suffered from clear signs of trauma, and investigators concluded the deaths were homicides.
A likely suspect was quickly identified, and due to a Bay Area-wide coordination of alerts through other agencies. the Redwood City Police Department located the suspect at a train station in Redwood City and arrested him.
The 34-year-old was in a relationship with the female victim and the boy was the suspec’s biological son.
The identity of the victims and the suspect have not yet been released.
"Heartbreaking incidents like this can have a profound effect on our community," the Antioch Police Department said in the statement. "The Antioch Police Department would like to extend our deepest condolences to the families of this unspeakable tragedy."