What happens if a society has the capability to 'treat' violence?

There was a book I read many years ago by Phillip Kerr (I think) called
the Philosophical Investigation. In the story there existed a society
where a part of the brain had been identified in a small number of
people (mainly or all men) that if treated with medication could stop
these people being violent. The drug was perfectly safe for physical
health but there was still a concern about the impact on mental health
and the ethics of punishing someone before they've committed a crime.

The tools used in psychiatry have the power to 'treat' violence and
murder. There are many tools in the psychiatric armentarium, not just
psychopharmaceuticals.

Psychaitry isn't always bound by medical ethics. There are political,
cultural and societal factors. The fear of the psychopathic killer
brought about the introduction of Community Treatment Orders - enforced
treatment with the threat of incarceration for more forced treatment.

There were many factors behind this legislation. It was a direct attempt
to reduce the homicide rate by people with mental illnesses. Enforcing
treatment could potentially save lives.

This could be extended. Anyone at risk of killing someone else could be
treated. I would guess that the best treatment would be clozapine.

Imagine this future society where people could be prescribed a drug that
reduced their life expectancy considerably for fear that they would
commit homicide.

Imagine a society where someone is punished in whatever form that takes
but without being proven guilty of a crime, i.e one that 'treats' people
who are at risk of violence but have not harmed anyone.

I would guess that most of the population would vote for the safest
option but would they accept benzodiazapenes and antidepressants in the
water supply? I.e. how would they vote if affect them.