[kcvl]

Exactly. Usually by their own hands such as drowning, driving a car into the river, chloroform, etc.!

[starvosan]

The gunman got around:

http://pittsburgh.cbslocal.com/2012/03/08/upmc-2-dead-7-injured-in-western-psych-shooting/
There were shell casings found on the second floor as well, reportedly.
... the gunman may have been using a 9mm gun.