The 24-year-old Santa Clara man arrested Feb. 20 for fatally shooting the 3-year-old son of his girlfriend was arraigned today on a murder charge.

Before he shot the child in the head at close range, prosecutors said Sergio Colin-Gomez was threatening his pregnant girlfriend, trying to force her to confess to infidelity, and telling her, “Don’t be stupid.”

“We are sickened and heartbroken at the senseless murder of Ivan,” District Attorney Jeff Rosen said. “Nothing we achieve in court, no jury or judge, can make up for the lost life of this innocent child. We will sadly but steadfastly do our job to make sure this person will never harm another.”

At approximately 2am on Feb. 20, Ivan’s mother called 911 and reported that her boyfriend had shot her baby. Santa Clara Police Department officers soon arrived in the area and contacted the suspect as he walked on the sidewalk of White Oak Lane. Colin-Gomez resisted arrest but was ultimately subdued and arrested, Rosen’s office said in a press release.

Prosecutors said evidence shows that Ivan and his pregnant mother were watching television in the apartment on the 3000 block of Poinciana Avenue when the defendant came home at 10pm. After the little boy fell asleep, the suspect began to aggressively accuse the mother of infidelity.

The District Attorney’s Office continued with this description of the tragedy.

“Fearing for her safety, the mother went to her son’s room and locked the door, according to the district attorney’s office. The suspect broke in, left, and came back holding a handgun.

“As he aimed it within a foot of the child’s head, the mother reached for the weapon. The suspect fired the fatal shot then fled the apartment.”