The trash-talking, pot-smoking star of "16 and Pregnant" and "Teen Mom 2" has badly damaged MTV's claim that its super-popular teen pregnancy shows were "cautionary tales . . . meant to cast a light on the harsh realities teens face when raising children at too young an age."
Evans has racked up charges of breaking and entering, stealing credit cards and possession of drugs in just her first year of MTV fame. And she faces up to six months in jail for her part in a brutal, videotaped beat down of a former friend that was all over the Internet last week.
Evans, 19, has been a ratings juggernaut for the network.
A new crop of underage moms was unveiled last week in a two-minute trailer for the upcoming season of "16 and Pregnant" -- and the previews promise more violence.
Meet Jennifer Del Rio of Riverview, Fla., who is trying to raise twin boys Joshua and Noah (born last October) while working toward a GED.
In the trailer, a fully enraged Del Rio is seen pounding on her boyfriend, then being restrained and yelling, "Say goodbye to your kids, Josh. You will never see them again," as he is led away in handcuffs.
"People have higher expectations for drama," says Brian Balthazar, editor of the pop culture Web site PopGoesTheWeek.com, which has been covering "16 and Pregnant" from the beginning. "They are going to need to have even more over-the-top characters, even more rebellious kids.
"I am sure they have cast a wide net for girls who could be potentially that much worse."
Domestic violence has become a key ingredient in MTV's recipe for ratings.
Last year, "Teen Mom" star Farrah Abraham of Council Bluffs, Iowa, had her mother arrested for assaulting her during an argument.
Just weeks later, tabloid darling Amber Portwood of Anderson, Ind., landed in jail for pummeling her baby daddy in front of their 1-year-old daughter.
In neither case did producers step in to help, and MTV only turned over video footage of the Portwood attack after receiving a subpoena.
The aggressive behavior is encouraged by MTV producers, says Season 1 cast member Whitney Purvis.
"They would take you in separate rooms, and then they would film me with my friends and my boyfriend with his friends and just get you to talk about the things you don't like about each other," she told ABC News.
"They want you to argue. They want you to talk about each other. They want you to get where you want to break up with each other to go stay at separate places."
All 10 episodes of the upcoming season were filmed last fall, prior to Jenelle's latest outburst.
MTV has made no move yet to modify the show in response to claims it is glamorizing pregnancy and exploiting its young cast.
"Since this drama has gotten them so much press, they may open up some of these shows and have to make some tough decisions about what they want to show and what they don't," Balthazar says. "But I think they are probably going to steer to the side of intense drama, chaos and arguments."