The car bombing outside a California fertility clinic, which killed one person and injured four others, appears to be driven by anti-natalist ideology, according to two senior law enforcement officials briefed on the incident.

A 25-year-old man the FBI believes was responsible for an explosion that ripped through a Southern California fertility clinic left behind “anti-pro-life” writings before carrying out an attack investigators are calling an act of terrorism, authorities said Sunday.

The FBI says the one person killed by a car bomb outside a California fertility clinic Saturday was the attacker. Andres Gutierrez has more.