Gary Head and Jenelle Evans in Wilmington, North Carolina on May 20, 2012. Credit: Ryan Turgeon/Splash News

Teen Mom 2's Janelle Evans and her on-again, off-again fiance Gary Head were both arrested and thrown in jail early Sunday morning -- and Head has been formally charged with assaulting Evans.

"Gary was charged with assault on a female, possession of marijuana, possession of drug paraphernalia, and possession of a controlled substance," Evans' attorney Dustin R.T. Sullivan tells Us Weekly. "A restraining order was put in place by the judge . . . Jenelle has already taken steps to try and protect herself from Gary."

The reality star, 20, was charged following her arrest as well for several misdemeanors, including "simple assault, possession of marijuana, possession of drug paraphernalia, and possession of a controlled substance," Sullivan says.

Evans, for her part, posted her $500 bond and was released Monday afternoon. Sullivan says Head's bond has been set at $1,500, although he wasn't sure if the Marine had been released.

Following Head's vicious assault, a source close to the mom to Jace, 2, tells Us it was just a matter of time before she saw Head's true colors.

"Gary had been extremely violent leading up to the event," the insider reveals. "He had been doing lots of yelling, and physical abuse, including pushing and shoving. This has gone on from the beginning (of their relationship)."

As for how Evans is holding up after the weekend? "She has bruises, scratches and red marks all over her body," the source says. "She's very fearful of what he is capable of doing."

Adds the source, "For Jenelle to get charged in this mess, I'm just amazed, because she is [the victim]."