"I grew up in a very conservative, religious family." This is how most radical leftists introduce themselves. Leftism doesn't start at birth for these people, they are indoctrinated into it fast at, roughly, the ages 16-25. Usually the moment they leave their family and go to college or move out into the workforce they go on a natural "journey" to find their own identity. Often this results in radicalism, most common at those ages, the fire of which burns out by their early thirties where their core political and ideological identity crystallizes.
In the worst cases, this inward journey is hijacked and corrupted by extremist ideologies like trannyism and communism, but also applies to the extremist right and satanists/luciferians, and Crowleyan new age babble, who often operate through sexual perversions to capture the psyche of the young adult. It happens fast.
So, the leftists using the identity of the family to find the identity of the shooter are retarded. This identity was most likely formed quickly over ~1-2 years in a warped pursuit of perversions and an in-group. Likely, there is little his family could have done. It's a disease that is intentionally spread, like AIDS, by discord trannies in current year.