Well, we can speculate about the poor, loving father, who only wants to see his daughter and he was driven to violence that was out of his character by the WTBTS, but in reality we don't know this is true.
People who are reactively violent often have a history of acting out with violence and trying to use force to get their way whenever they are under stress. Then they blame the external stressful circumstance instead of their own ability to cope in socially acceptable (non-violent) ways.
A few weeks ago, a poster on this board told me his JW daughter's teenage friend was chased around the house by her JW father with a hammer. She fled for her life to a sister's house and is afraid to return home. Now if she reports him and he gets shunned and he reacts violently and comes after her again, or the elders, did the society drive him to that behaviour due to their shunning policy?
A woman in the congo I grew up in was murdered by her df'd husband who was being shunned. He held her and his two children hostage at gunpoint in a police standoff. The police talked him into letting the kids go then he shot his ex-wife and killed her. Just for the record, she divorced him and he was df'd for being abusive and violent. A decade later, I saw him interviewed in prison, for a tv documentary and he still blames her and the WTBTS for driving him to violence. According to the logic many are using on this thread, he would be justified in blaming the WTBTS.
My point is this: there are many reasons that people are violent, mental illness being only one of them. We don't know any of the history on this person but many are automatically quick to blame the society for anything that goes wrong in their lives. If someone is violent and abusive and doesn't get df'd, it's automatically the society's fault. If someone is violent and gets df'd, then that's the society's fault too. There is very little balanced perspective in the blame game being played here.
The society is psychologically manipulative and coercive and they use fear, guilt and shame to try and control people (as do most religions and the Bible). However, they have never advocated the use of physical force to control anyone (which is more than can be said for most other religions), so to lay the responsibility for the physical violence of everyone remotely associated with them at their doorstep is a huge stretch of credulity.
Cog