PROVO — It sounds like an episode of "Law and Order" gone awry.

Girlfriend stabs boyfriend while he's sleeping. Both blame the ex-roommate, who they say is angry about being kicked out of the apartment.

Ex-roommate is arrested and sits in jail for months before a witness comes forward to implicate the girlfriend in the stabbing. Prosecutors drop charges against the ex-roommate and charge the girlfriend, who later pleads guilty.

Now the stabbed boyfriend faces his own charges for allegedly lying to police.

It's a twisted, convoluted story and one that has prosecutors pretty upset.

"We rely on witnesses and victims of crimes day in and day out to tell the truth," said prosecutor Chad Grunander. "When they don't, it can certainly result in serious miscarriages of justices. We want to correct that."

Although Grunander can't give back the months that ex-roommate Tyler Calton spent in jail, he can make sure the appropriate people are punished. That is why he charged the girlfriend, Melissa Elkins, and why he filed charges Wednesday against the boyfriend, Eric J. Davis, for obstruction of justice and providing false information to police officers.

Police say Davis told them he made up the story about Calton because he was "scared" of Elkins, his girlfriend, according to a police affidavit filed in 4th District Court.

Such fear seems strange, said Elkins' attorney, McKay King, because the couple is still together. Besides, Elkins, at 5 feet 6 inches and 110 pounds, has consistently maintained she doesn't remember what happened that night in January, King said.

Elkins, Davis and the witness told police they had been drinking heavily that night, King said.

Elkins, who has no criminal history, pleaded guilty in May to simple assault and obstruction of justice and was ordered to complete drug treatment instead of jail time to address her alcohol issue, King said.

But the story gets weirder.

When Calton was arrested for the stabbing, officers found marijuana and paraphernalia on him, so he got slapped with a drug charge. He insisted he hadn't committed the assault, but still faced the potential of 15 years in prison if convicted of possessing pot with the intent to sell it.

Both Calton and his attorney, Shawn Howell, agreed it would be better to take a plea deal than face a jury. So Calton pleaded guilty to aggravated assault and possession with intent to distribute, which prosecutors reduced from a second- to a third-degree felony.