According to the LAist, Bartkus appeared to describe himself as being promortalist and misandrist on a website that surfaced after the bombing and could be heard in an audio recording saying, “Basically I’m anti-life. And IVF is like kind of the epitome of pro-life ideology.” […] Nihilists believe that life is meaningless. While promortalists and antinatalists also don’t value human life, Katherine Keneally, director of threat analysis and prevention US for the ISD, says Bartkus’ views were somewhat distinct from nihilism because of his belief he was on a mission.
Source: wiktionary