Boulder District Attorney Mary Lacy on Wednesday publicly cleared the entire Ramsey family of any involvement in the murder of JonBenet Ramsey, a fatal error that only complements the repeated misjudgments she has made in the case since she was elected.

Her decision was based on the fact that minuscule particles of foreign DNA that were found in JonBenet’s underpants apparently match skin cells discovered on the waistband of JonBenet’s leggings. Although this DNA may match, Lacy’s own words prove this particular DNA may not even be relevant.

In 2006, after Lacy extradited John Mark Karr, an otherwise innocent man, from Thailand, to erroneously charge him with the murder, she announced: "The DNA could be an artifact. It isn't necessarily the killer’s. There’s a probability that it’s the killer’s. But it could be something else."

Forensic expert Henry Lee most likely would agree that the foreign DNA in question most likely is "artifact," because he always has said he believes it actually is the result of contamination and that it is completely unrelated to the crime.

In fact, early on in the case a panel of pediatric experts determined that JonBenet was a victim of long-term sexual abuse, which would mean her killer probably is someone she knew.

Steve Thomas, the Boulder Police Department’s lead detective who logged more hours on the case than any other officer, publicly endorsed the theory. Thomas believed that Patsy Ramsey, the little girl’s mother, was the real killer.

Although the Boulder Police Department never officially commented on Thomas’ theory, it is common knowledge in the Boulder law enforcement community that Thomas was echoing the conclusion of the actual investigation.

At no time did the Boulder Police Department believe JonBenet was killed by an intruder; nonetheless, Lacy persistently has done everything in her power to manipulate public opinion in favor of the intruder theory. Although that theory should continue to be explored until the case is solved, Lacy’s motivation for promoting it with so much passion is suspicious.

It’s no secret that in 1997, when Lacy was a sex-assault prosecutor under then-DA Alex Hunter, she was furious when he did not appoint her to work on the case. Because Hunter and the police shied away from the intruder theory, many law enforcement officials often wonder if Lacy’s attempts to prove them wrong are driven more by her personal feelings than by the actual pursuit of justice.

Shortly after taking office, Lacy announced in 2003 that she believed the Ramseys were innocent, an unusual and inappropriate statement for a prosecutor to make during an ongoing investigation.

In fact, during the Karr debacle, Lacy also said that "no one is really cleared of a homicide until there’s a conviction in court, beyond a reasonable doubt. And I don’t think you will get any prosecutor, unless they were present with the person at the time of the crime, to clear someone."

There is no question the Ramsey case has been unusually long, and the Ramsey family has suffered terrible heartbreak and undeserving cruel attacks from the media. Although the family deserves compassion, JonBenet deserves justice and Lacy’s motivation is misguided.

Almost nothing Lacy has done has been based on the solid, investigative work compiled by the Boulder Police Department or the opinions expressed by the FBI. Lacy, who had no official contact with the Ramsey case under the leadership of Hunter, has disregarded the opinions of every law enforcement agency and forensic expert who worked on the case.

Her arrogance and incompetence is beyond compare.

Despite her repeated attempts to convince the public that her belief is grounded in the highly respected science of DNA, it appears that her rationale is flawed. If Lacy were serious about solving the Ramsey case, she would re-invite the original police investigators and FBI agents, who know the case inside and out, to come back and advise her.

She’ll never do that, however, because for Mary Lacy none of this really is about JonBenet — it’s about her legacy and her ego.

Jeffrey Scott Shapiro is an investigative reporter who worked on the JonBenet Ramsey case for more than 10 years. He practices law in Washington, D.C., and can be reached at jshapiro@ufl.edu.