FORT COLLINS, Colorado (CNN) -- Tim Masters is no longer the slim, shaggy-haired 15-year-old he was when Peggy Hettrick was murdered, mutilated and dumped in a field near his home.
Tim Masters is serving a life sentence for a murder conviction that is now being questioned.
Goateed and bespectacled with a slightly receding hairline, Masters, now 36, sat quietly in court this week, occasionally flashing a boyish smile as his defense team worked to poke holes in his 1999 murder conviction.
The conviction followed a 12-year investigation that Masters' defense attorneys say is flawed because it focused on building a case against a suspect instead of solving a murder.
Attorneys David Wymore and Maria Liu want a judge to toss out Masters' murder conviction.
In hearings that began in September, the attorneys are drawing out evidence they hope will persuade Judge Joseph Weatherby to give their client another chance at justice.
They allege that police used deceptive investigative tactics and that prosecutors withheld key evidence that would have cast a kinder light on Masters, who is serving a life sentence.
Wymore said he's been met with only "obfuscation, obstruction, stonewalling, stiff-arming" from police and prosecutors in his attempts to vindicate Masters.
Fort Collins police Lt. James Broderick, who once led the investigation, would not discuss the specific allegations now at issue but he stands staunchly by his work in the case. However, he said, if a judge rules the evidence warrants another trial and a new jury frees Masters, he will accept it.
"The last thing in the world I want is someone convicted of a crime they didn't do," he said.
The Masters case is the talk of this college town of 137,000 nestled in the foothills of the Rocky Mountains. Fort Collins, home to Colorado State University, prides itself on its quality of life. Money magazine last year called it the nation's best place to live.
A prosecutor has been appointed from a nearby court district to look into the case. Two of the prosecutors in the original Masters trial are now local judges.
In a four-page letter to the specially appointed prosecutors, Masters' lawyers said there is no justifiable reason to deny him a fresh trial. Wymore said his message is clear: "Give up."
Not so fast, said District Attorney Don Quick of the 17th Judicial District, whose office assigned the special prosecutors who are still collecting documents and providing them to the defense as they get them. The prosecutors are trying to determine what was and wasn't given to Masters' defense team, and what material, if any, should have been disclosed, Quick said.
"I'm not throwing my hands up," he said, but if key evidence favoring the defense was withheld, "I think the original prosecutors need to take the stand and say why."
Nathan Chambers, one of Masters' lawyers at the original trial, testified Wednesday that the prosecution gave him some information on other potential suspects in the slaying, but it "was weaker than circus lemonade."
He testified that he never knew of an eye surgeon who also lived near the field where Hettrick's body was found. Dr. Richard Hammond, according to court testimony, killed himself in 1995 while awaiting trial on charges that he surreptitiously filmed the genital areas of women while they used his downstairs bathroom.
At least one investigator, according to court documents, questioned whether Hammond might be involved in the Hettrick slaying, but the hunch apparently was never followed up, according to testimony.
Not much is known about Peggy Hettrick or how she met her killer. What is known is that she died February 11, 1987, at the point of a blade at least 5 inches long. It was delivered with such force that it fractured a rib, according to court documents.
The 37-year-old redhead's body was taken more than 100 feet into a field near the trailer Masters shared with his father, Clyde. Her arms were outstretched. Her underwear was pulled down and her shirt was lifted to reveal a neatly excised nipple, court documents show. Part of her genital area also had been sliced away.
A passerby found Hettrick's body and called authorities. Police quickly learned that Masters -- taking his normal path through the field to meet the school bus -- paused a few feet from Hettrick's body and continued on without calling police, court documents show.
That put Masters atop the Fort Collins Police Department's list of suspects.
Police searched his home the next day. There, they found six survival knives displayed on a bureau in Masters' bedroom, each with a blade longer than 5 inches, according to court documents.
Police also found numerous narratives and drawings that prosecutors later called "cruel and grotesque." Many of the sketches depicted murders. Police found more such material in Masters' locker at school and in his backpack. See the 15-year-old Masters and some of his sketches »
On the kitchen counter at his father's house was the death certificate for his mother, also a redhead, who had died from health complications almost to the day four years earlier.
Lacking physical evidence from the crime scene, police used the circumstantial evidence to paint a picture of an anti-social youngster so wracked by abandonment from the untimely death of his mother that he took sadistic revenge on a passing woman who resembled her.
Internal police memos presented as evidence in the current hearing show the Fort Collins Police Department worked with the FBI to apply psychological pressure and incite a reaction from Masters on the anniversary of the Hettrick murder. The FBI, according to the memos, promised to disavow any knowledge of the sting if it was uncovered.
According to the memos, authorities:
"They're chumming the waters, your honor. They're trying to get a bite," an incensed Chambers told the judge this week.
"I like cops. I represent cops," he said. "For police officers to be so utterly devious is heartbreaking."
Jack Taylor, one of the lead investigators on the Hettrick murder case, confirmed the police tactics described in the memos in his testimony Thursday.
Masters didn't have the violent response that police suspected he would. Had Chambers known about the sting, he said, he could have used it to show that his client did not fit a purported profile that prosecutors used to portray Masters as a psychopath.
"None of this is given to me. None of it," Chambers told the judge.
Wymore, Liu and Chambers say the volume of exculpatory evidence that the prosecution had but never presented to the defense during Masters' 1999 trial is astounding.
Discovery rules dictate that prosecutors must turn over police files, lab reports and other evidence -- both incriminating and favorable to the defendant -- before the trial.
Failure to do so can result in severe sanctions. A recent high-profile example is former Durham County, North Carolina, District Attorney Mike Nifong. He was disbarred over his failure to turn over lab reports and for his overzealous handling of the sexual assault case involving members of the Duke University lacrosse team who were cleared of all the charges against them.
In the Masters case, prosecutors and police -- save a few members of the investigative squad who have become skeptical -- have long stood by their work.
They say Masters was arrested after an exhaustive, 12-year probe that followed him from high school to the U.S. Navy and back to the civilian arena after an honorable discharge.
Broderick, the former lead investigator, agrees that the case is based largely on circumstantial evidence and that some of those pieces of evidence don't raise suspicions by themselves.
But when you put it all together -- the knives, the drawings, the anniversary of his mother's death, Masters' failure to report the body -- it creates a "mosaic" that points to Masters as the killer, he said.
"Twelve people looked at that stuff and came to the conclusion that this guy is guilty," Broderick said. "My job is to present the information. My job's not to ensure the jury follows my logic."
Broderick, who has been sitting at the prosecutors' table during this week's hearings, said that until he sees new evidence, he will continue to believe Masters is Hettrick's killer.
"I can't go to bed at night knowing all the incriminating details," he said. "If I don't present that to a jury, I haven't done my job." E-mail to a friend