Criminalizes participation in criminal street gang.

S 1370 makes it a fourth-degree crime to knowingly and actively participate in a criminal street gang while promoting or assisting others in committing specific violent or serious offenses. It directly affects individuals who engage in gang-related activities tied to crimes like robbery, carjacking, assault, sexual assault, arson, burglary, kidnapping, extortion, witness tampering, or violations of drug/firearms laws. The bill defines a "criminal street gang" as three or more people meeting specific criteria (e.g., tattoos, clothing, or documented criminal history) who have committed listed offenses within the past five years. Violators face up to 18 months in jail, a $10,000 fine, or both. The law takes immediate effect upon enactment.