Montgomery County police, desperate to solve the case of little Michele Dorr, who had been missing since 1986, last year "trumped up" murder charges against an "emotionally vulnerable" Hadden Clark, Clark's lawyers told a jury as he went on trial yesterday.

But the 12 jurors who will determine whether Clark killed the 6-year-old did not--and will not--hear a key fact about him: that six years after Michele disappeared, Clark killed a young Bethesda woman who vanished from her home.

In a ruling handed down just before opening statements in Clark's trial began, Montgomery County Circuit Court Judge Michael D. Mason said jurors would be unjustly swayed if they knew about Clark's 1993 conviction for murdering the young woman, Laura Houghteling.

Mason also ruled that prosecutors may tell jurors about blood allegedly discovered on a knife found among Clark's possessions but that they may not mention the DNA tests that prosecutors say link the blood to Michele's DNA. Mason ruled that the results of the DNA tests were more prejudicial than reliable.

Clark's conviction in Houghteling's death and the results of the DNA tests had been considered key portions of the prosecution's case against Clark, 47. But in opening statements, prosecutors focused on what officials consider to be their other strong evidence against Clark.

Assistant State's Attorney James Trusty told jurors that Clark became "violently ill" when police questioned him a week after Michele vanished and that he later described to fellow prison inmates how he'd almost decapitated the child. But Clark's attorney said that his client was at work the afternoon Michele disappeared and that the jury should look more closely at Michele's father, who reported her missing.

Carl Dorr has said he last saw his daughter heading outside to play in a small, plastic pool in his back yard, which was two houses down from the Silver Spring home where Clark had lived with his brother.

Trusty told the jury that prosecutors would show that Clark discovered Michele in his niece's bedroom May 31, 1986, among the dolls and stuffed animals where she may have gone in search of her 5-year-old playmate.

And there, Trusty said, Clark cut Michele so deeply across her chest that he almost decapitated her. Michele's body has not been found.

When Montgomery police detectives questioned Clark about Michele a week after she disappeared, Trusty told jurors, Clark vomited and suffered a sudden bout of diarrhea before saying, "Sometimes I black out and do things I don't remember."

But one of Clark's lawyers, Assistant Public Defender Donald Salzman, told jurors that his client had clocked in at his chef's job at 2:46 p.m., about a half-hour after Dorr told police he had last seen Michele.

"The trumped-up case against Hadden Clark is nothing more than a mirage put together by people desperate to solve the mystery of this missing little girl," Salzman said.

Clark, wearing a long-sleeved, navy-blue shirt, often stared at the packed courtroom of about 70 onlookers yesterday.

His gaze often seemed to focus on Montgomery police Detective Edward Tarney, the lead investigator in the case who sat in the front row beside Michele's mother, Dee Dee Appleby.

Michele's father held hands with his wife, Margie, and stared straight ahead as the defense made him, instead of Clark, the focus of their case.

Salzman suggested that Carl Dorr, who was in a bitter custody dispute with his former wife, had a motive to snatch Michele. Shortly after Michele vanished, Salzman told jurors, Dorr told his former wife that Michele was buried in his basement.

When police looked behind paneling that appeared to have been disturbed, they found a space "big enough to hold a little girl like Michele," Salzman said.

Trusty told jurors that Carl Dorr, who was grief-stricken and under intense pressure from detectives as the initial suspect, suffered two nervous breakdowns and merely told others of his hallucinations.

CAPTION: Jurors will not be told that Hadden Clark killed a young Bethesda woman six years after Michele Dorr, 6, disappeared in 1986.