Profile - A Model Organism

October 2006
DNA: The molecule that encodes genetic information. The molecular basis of heredity, located esp. in cell nuclei.

Mitch Morrissey is nuts for DNA. You could say he’s obsessed by it. Walk into his eighth-floor office in the Wellington Webb Municipal Building and it’s the first thing you see—a giant plastic model of a double helix, the spiraling ladder that revolutionized forensics. He’s been known to wear a necktie emblazoned with the pattern, and in conversation he tosses around terms like “allele,” “polymorphic,” and “hypervariable” with such ease you’d think he’s a scientist, not Denver’s district attorney. Anyone who mentions his name invariably follows it up with those three letters. It’s like a title: Mitch Morrissey, DNA.

In 1988, a DNA test first exonerated a man accused of murder and rape, and incriminated another. Morrissey remembers thinking, This is the science of the future, and I need to know it. He buckled down and spent untold hours in CU’s medical library, poring over books and painstakingly deconstructing the complicated, brain-numbing double helix. “He decides certain things in his life,” says Floyd Ciruli, a political pollster and longtime family friend. “[One was] this idea of getting completely focused on DNA, which is boring and intense and not something you just kick around and talk to the guys about.”

Morrissey studied and read, memorized and quizzed, discussed and learned. He sought the expertise of Dr. William Seltzer, former director of the CU Heath Sciences Center DNA Diagnostic Laboratory, and befriended Greggory LaBerge, a forensic scientist working in Denver’s crime lab who sketched diagrams for Morrissey to take home. Morrissey was unstoppable—the guy with a political science degree was becoming an expert at a science that would change the world.

By this time, Morrissey had worked at the DA’s office for six years. He’d won the admiration of colleagues, having proven himself to be a natural trial attorney with razor-sharp prosecutorial judgment. “After our first trial we did together, I was beginning to believe that trial talents and trial abilities must be inherited,” says David Conner, assistant U.S. attorney, who first met Morrissey in the 1980s when they were both rookies. “He was astronomically good at it, given his experience.” But when Morrissey dove into DNA research, his fellow attorneys thought he’d gone a step too far. His dad, Mike, agreed, lumping the new science into the same category as the “bullshit” lie-detector test. But Morrissey’s tenacity paid off in 1989 when he prosecuted Denver’s first DNA case, The People v. Jeffrey Fishback, and won. Morrissey, calling on Dr. Seltzer to weigh in on a semen sample, conclusively tied Fishback to a sexual assault and burglary. Fishback went to prison for 58 years.

In the eight years since that case, Morrissey has continued his study of the ever-evolving science—and he’s now considered one of the nation’s top DNA experts. He’s been asked to work on such high-profile criminal investigations as Boulder’s JonBenét Ramsey case and the Bryson Knight murder trial, which was featured on ABC. His website,, logs forensic evidence and DNA case law, and was referenced in the Scott Peterson murder trial. He travels to conferences around the globe, and speaks at many of them. Along the way he’s won the respect of Dr. Henry Lee, the prominent scientist who testified during the O.J. trial. “He took the time,” says Dr. Lee. “Mitch needed to understand the scientific—go down to the laboratory, understand the legal issues. I would consider him a pioneer in helping [get] DNA into the court.”

Closer to home in 2003, Morrissey, LaBerge, and Lt. Jon Priest from the Denver Police Department pioneered the Cold Case Project that utilizes DNA to solve cold cases—more than 4,000 sexual assault and murder cases have been reviewed and 20 charges filed in cases dating back to 1992. Today, largely because of Morrissey, Denver is one of just five cities granted $500,000 by the National Institute of Justice to study how DNA analysis impacts property crime. When Morrissey was elected DA in November 2004, LaBerge hand-constructed the DNA model that now stands in his colleague’s office—a symbol of the 10 cases Morrissey’s won using DNA as his weapon.

Informed consent: An individual willingly agrees to participate in an activity after first being advised on the risks and benefits.

On nice days the Denver district attorney drives a sky-blue, convertible Miata. It’s used, of course; it would be unlike him to splurge on anything glossy and new. He drove his last car, a beat-up BMW, into the ground, only retiring it when a mechanic deemed it unsafe. Yes, on a nice day, you might find Morrissey cruising along, alone but for his West Highland terrier, Jake, hunkered low in the wheel well, a tennis racket in the back and the wind ruffling a thick coif of smoke-colored hair.