There is growing evidence that some criminals can have genes which may pre-dispose them to be more violent or aggressive than others. Equally, neuroscience studies are reporting patterns of low activity in the frontal cortex of the brain, which controls our impulses, emotions and decision making, with those who commit crime and possible differences in brain structure, such as the amygdala, which can be smaller in those who are prone to aggression and violence.
Saying all that, social and psychological factors are also very important in how a person will behave. Upbringing, experience, abuse, mental health, substance misuse and socioeconomic status along with their general environment are all significant factors which affect why an individual behaves in a certain way, including carrying out criminal activity.
I would say it is a complex mix of biological factors which may increase the likelihood of an individual committing violent crime, and social factors which can make an individual more prone to be involved in crime. I think what is important also is human agency and free will. All action and behaviour at the end of the day has an aspect of choice in there, it just may be that for some, that choice is harder than for others.