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

Authorities called the attack terrorism and said Bartkus left behind nihilistic writings that indicated views against procreation, an idea known as anti-natalism. Here’s what to know about the case.

A 25-year-old man believed to be responsible for an explosion that ripped through a Palm Springs, California, fertility clinic left behind “anti-pro-life” writings before carrying out the attack.