volveré y seré millones
There's evidence, but it has more links to social behavior than what you can pin to individual actions. And the same media can be cathartic (a sublimation or deviation from violence) or propaganda (tending to promote or naturalize violence) to different degrees and people in different situations, and you have the egg and chicken dilemma between media and other actions, as they provide feedback to each other.
There is no proper evidence that video games are linked to violence. Some say there are negative, some say none and some say there are positive effects on prosocial behavior.
This means judging the role of media is complicated or confusing, often lost in many factors, relations, and interpretation, but not that it isn't linked.
Censorship, while occasionally acceptable, tends to do more harm than good and the general way to work with this is by longer term cultural action (education, publication habits, consumer expectations, consciousness campaigns, public policy drives and so on), which has relative effects and is in constant debate.
It's social and particular within that, not just "the person", and "the material" is imbued with a heavy ideological charge which has human wills (people) behind it. Individuals have limited power over their environment, you can't stop judging them, but if you elude social responsibilities and pressures that condition and dominate them, the causes of most injustice and issues aren't addressed.
Its the person. Not the material.