no, they literally, by definition aren't
Type of: act of terrorism, terrorism, terrorist act. the calculated use of violence (or the threat of violence) against civilians in order to attain goals that are political or religious or ideological in nature; this is done through intimidation or coercion or instilling fear. coup de main, surprise attack.
"TO ATTAIN GOALS THAT ARE POLITICAL OR RELIGIOUS OR IDEOLOGICAL IN NATURE"
have 1 retardo shooting 3 people (which is what it takes to count as a "mass shooting" even tho its only 3 people) is not always done for relifious or political reasons, they do it bcuz they are mentally ill