Last Sunday’s “lone wolf” terror attack at a church in Samarinda, East Kalimantan, seemed like another random act of Islamic State-endorsed violence. A 32-year-old perpetrator killed a toddler and injured three others with homemade bombs at Oikumene Christian Church. Although the attack seems arbitrarily violent, it was actually premeditated. And the perpetrator is linked to a homegrown extremist network and the prison system, both major factors in his radicalization.