"This is America, where you can find a gun easier than mental health services,"
Can you, really?
Certainly in most areas, there are more gun stores than mental institutions (because mental institutions are much more expensive than gun stores), but provided the mental institutions are there is it really easier to get a gun than to check into a mental institution?
To buy a gun in the United States, you must fill out form 4473, recording the sale of the firearm. A background check will be performed. The whole process takes half an hour to several hours. Of course, you can buy guns from private sellers without a background check, but this is actually much more difficult than doing it the former way (speaking from experience) for most people.
Here's the process for checking into a mental institution from eHow.
I'm absolutely positive the perpetrator's thought process went exactly like this:
"I feel depressed. I wonder if there are any mental institutions that I could check in to. No? Darn. Well, then I guess my only choice is to shoot up the nursing school."