New York is seeing the hidden toll of legal weed: violence, psychosis and mayhem

John Sutter : Debrina Kawam , a troubled New Jersey woman, was set on fire on an F train and burned to death.

He says Sebastian Zapeta-Calil , an illegal immigrant from Guatemala , spent $ 30 daily on K2 , a synthetic cannabinoid.

K2 became a scourge in New York City about a decade ago , with erratic, sometimes violent, behavior.

Sutter says legalization of marijuana may have increased K2 ’s availability.

Linking any specific crime to the use of legal marijuana or illegal synthetic cannabinoids is hard enough, much less correlating legalization to broader crime trends. But there certainly seem to be enough pot-related incidents occurring on the streets and in the subways of New York to raise the question of whether our laissez-faire experiment with drug use is working..