being “disturbed” has nothing to do with mental diagnosis. (“mental imbalance” isn’t in the DSM either 
)
plenty of people who are perfectly sane commit horrible acts, and the vast majority of “mentally unbalanced” people are just as, if not more, peaceful than so called “normal” folks.
killing innocent people is disturbing. it’s fair to call someone who decides that it is a good idea to shoot innocent people disturbed.
