Which factor is the strongest predictor of future violence in clients?

The strongest predictor of future violence in clients is previous violent behavior. This is supported by extensive research that shows a direct correlation between an individual's past actions and their likelihood of repeating those actions in the future. If a person has exhibited violent behavior in the past, it suggests patterns of aggression or a potential inability to control impulses that can resurface, particularly in high-stress situations.

While a diagnosis of mental illness and a history of substance abuse can be contributing factors to violence, they do not consistently predict future violent acts to the same extent as a history of violent behavior. Non-compliance may indicate challenges with treatment adherence but doesn't necessarily correlate directly with the propensity for violence like previous violent acts do. The most robust indicator remains the documented history of violence, as it reflects not only a tendency but also a learned response to various stimuli or circumstances.