“Even serious crime can be senseless,” said Jack Levin, co-director of Northeastern University’s Brudnick Center of Violence.

“What does a rampage shooter get from his killing spree? He makes no money and doesn’t know his victims. Not unlike a rampage shooter, those who commit petty and useless crimes may have the same motive: revenge.

“But not revenge against a particular individual; instead, the offender’s crime is symbolic. He feels like a pariah or an outsider and seeks to get even with his school, his community, his country, or even with all of humanity,” Levin said.