Expansion of mental healthcare access is definitely exaggerated in terms of how much it will reduce gun violence, but in this case, Holmes did have a history of mental illness that was left untreated for most of his adult life. He should have had easier access to mental healthcare, but the important variable in preventing the shooting is that he should not have had the ability to purchase a gun based on his mental state.
There's lots of signs and indicators that point to mental instability that your average mentally ill person doesn't know about.
