Cape Fear

It had been a frustrating slog for the Massachusetts State Police; the Cape Cod winter was as cold as their three-year investigation into the murder of Christa Worthington.

Then came a sudden, unexpected announcement in the thaw of spring in 2005.

Rob Welsh [prosecutor]: Last night at approximately 7:15 p.m., detectives from the Massachusetts State Police detective unit assigned to my office arrested Christopher A. McCowen, age 33, for the 2002 murder of Christa A. Worthington. 

The arrest was triggered by when forensic evidence found on the victim matched the DNA of one man.  But the people of Cape Cod were in for a surprise when they saw the person the police had in handcuffs.

It wasn’t an old lover, the the state was now saying. Far from it.

Assistant District Attorney Rob Welsh said the laboratory match would be the foundation of his rape and murder charges against Christopher McCowen.

Welsh: He was an individual who worked for the garbage company. There was no evidence that he knew Christa Worthington … beyond simply picking up the garbage and perhaps occasionally waving.

Because Christa was a customer on his garbage pick-up route, McCowen was someone investigators interviewed just after the murder. A year later they went back to him for a DNA saliva sample and still another year passed before they got around to testing it.

The forensic tardiness was an embarrassment to the cops but once the match was finally made the fog of suspicion lifted from Christa's former lovers, who were no longer suspects.

Tony Jackett: There's a sense of relief.  You know -- it's been an ordeal from the very beginning.

The prosecutor got ready for what might be a career-making case.

Welsh: I have not been in a case that has garnered so much media attention ... or one that lasted so long.

More than four years after her death, the Commonwealth of Massachusetts was ready to try someone for the murder of Christa Worthington.

Seated in the venerable colonial-era courtroom of Barnstable, Mass., the defendant had pleaded not guilty to the charges of first degree murder, aggravated sexual assault and burglary.

NBC video State: McCowen changed stories Watch excerpt of the prosecution's opening statement Dateline NBC

In his opening statement, the prosecutor told the jury that on the last night of her life, Christa had come face-to-face with Christopher McCowen. There was a struggle and she lost. She was raped and stabbed in the chest on her hallway floor.

Welsh: Her death was not instantaneous, she had bruises and abrasions all over her body ... And this defendant was completely indifferent to her suffering.

The prosecution's first witness put another exclamation point to the ghastly story.

Tim Arnold, the onetime boyfriend, told the jury his account of returning a borrowed flashlight on a Sunday afternoon, only to find Christa sprawled off the kitchen with her daughter Ava apparently nursing from her, or so he thought.

Arnold: I saw Ava's head pop up, but her mother didn't answer.
Welsh: And what was the next thing that happened, sir?
Arnold: I went over to see what was the matter. There was blood around her head.

The prosecutor painted a picture of the frantic arrival at the isolated cottage of police officers, paramedics and family members from across the road.

Paramedic: We actually wanted to cover the victim in the nearest thing that was -- that we found was a -- an afghan that was on a couch nearby.

Crime scene experts recounted how they recovered semen, saliva and skin cells found on the victim. The state's DNA expert, Christine Lamire, told the jury of the DNA match she found to one those samples in her lab.

The odds of the genetic material belonging to anyone other than Christopher McCowen was astronomical.

Welsh: One in 199.8 billion match, is that correct?
Lamire [DNA expert]: In the African-American population, yes. 

There were two supporting pillars in the case against McCowen: the DNA that lab experts said was his and the story he later told police when he was confronted about that evidence.

The lead investigator in the interview with McCowen after his arrest was state trooper Christopher Mason. The session lasted six hours.

Dennis Murphy: And then the officers question him in there what -- how many stories, five, six different stories, huh?
Welsh: There were numerous versions told.

The police didn't tape record McCowen's interview, but they did draw up a 29-page statement later.

Here's the story police say he finally settled on:

McCowen said that after a Friday night of partying, he and a friend drove to Christa's house around 1:30 a.m. McCowen said that after he and Christa had consensual sex in the living room, she heard his buddy in a room next door stealing things.

Christa, furious, confronted the friend in the driveway outside the house.  A fight ensued, and the two men beat the helpless woman into unconsciousness. 

Rob Welsh: I believe the quote is 'I still can hear her head hit the ground.  She hit the ground hard.'

Then the state trooper says McCowen described how he watched his friend drag the woman back inside her home.  The trooper said McCowen even drew a layout of the interior of the house.

And driving the knife into her chest?  The trooper said McCowen claimed innocence, saying his buddy actually did the murder.

That buddy, a truck driver named Jeremy Frazier, testified and denied ever going to the Worthington house with McCowen after their night of partying.

Saying that he and McCowen went their separate ways that night, Frazier claimed he crashed on another friend's couch to sleep off his buzz.

Welsh: There was no physical evidence linking Jeremy Frazier to the scene … We weren't going to charge Jeremy Frazier.  Jeremy Frazier had an alibi.

During the trial, the prosecutor asked point blank: “Did you kill Christa Worthington?”

Frazier’s response? "No, I didn't."

The prosecutor had finished the methodical brickwork of his case against Christopher McCowen.

He then told the jury how the murder likely happened -- how the crunch of a car up the driveway must have jolted Christa Worthington awake; her stepping outside to confront an unexpected visitor. It was one man, not two.

"The defendant Christopher McCowen went up to Christa Worthington's house early Saturday morning between 1:30 and 2:00 looking for sex," Welsh told jurors.

Welsh: She's really beaten to the point of helplessness ... dragged to that door, the door is forced in and then she's raped, stabbed.
Dennis Murphy [Dateline correspondent]: What a horrendous end.
Welsh: It is a horrendous end.

But it's not the defense's account of that night.

They claim Christopher McCowen didn't kill Christa Worthington, and one of New England's most able criminal defense lawyers was about to tell the jury why the cops had arrested the wrong man.