What many politicians try and hide is the relationship between a decrease in care for the mentally ill and the increase in crime.
Seems that the public, particularly in the US where a mentally ill person with access to guns is a bad combination, are fully aware of the root causes of the issue.
Probably where the saying “guns don’t kill people, people kill people” came from.
Below is a survey on the causes of mass shootings in the US. seems pretty legitimate to me.