Jenelle Evans ARRESTED -- Heroin & Assault

Jenelle Evans is back behind bars -- the "Teen Mom 2" star was arrested in North Carolina today for possession of a BUNCH of heroin ... and is also accused of attacking her husband, TMZ has learned.

According to court documents obtained by TMZ ... cops discovered 12 bindles of heroin in Jenelle's possession when they arrived to her home following an alleged domestic dispute with her husband, Courtland Rogers.

FYI -- a bindle is commonly known as a small paper packet used for storing drugs.

According to the docs, Evans was also found to be illegally in possession of Percocet (a prescription painkiller) ... as well as plastic wrapping paper and a glass smoking pipe, which is considered illegal drug paraphernalia.

As for the assault charge, cops say Evans struck Rogers with a piece of furniture during a domestic dispute.

Rogers was arrested too -- cops say he assaulted Jenelle by "hitting her on the neck and striking her with a closed fist on her head."

Cops say Rogers was also in possession of heroin with intent to manufacture, sell, distribute ... and drug paraphernalia. According to police, both Evans and Rogers denied possession of the heroin ... which is why they were both charged.

At the time of her arrest, 21-year-old Evans was also served with a warrant for failing to pay child support.

Evans has a history of legal problems -- she tested positive for marijuana and opiates while on probation ... and she was also involved in an epic girl-on-girl brawl in 2011.