When Hennepin County Medical Examiner Andrew Baker is called to testify in courtrooms, his presentation tends to be somber and focused on the facts of a specific case.

In a 75-minute presentation last week for law students, he offered a slightly less grim overview of his work, nonetheless showing many graphic slides from the morgue, including the needle track marks underneath the skin of an addict, plaque-filled arteries, stiff bodies, lividity (the pooling of blood in the body that can help pinpoint the time of death), the charred remains of a fighter pilot who crashed into the ground, and examples of shotgun blasts from both short- and long-range.

He also sought to dispel myths about forensic pathology, explaining that he loves the original "Law & Order" TV show but is a "conscientious objector" to the CSI franchise, which he and colleagues call "Can't Stand It."

Baker talked about the night in August 2007 when the Interstate 35W bridge fell into the Mississippi River. When he was alerted to the collapse, he was at a microscope scrutinizing a slide of heart tissue full of tiny dots, a telltale sign of disease. The cellular minutiae was the evidence of an undiagnosed heart disease that he later would give to parents to help explain their toddler's sudden death.

The microscopic evidence and the mass disaster illustrate the two ends of the medical examiner's work.

TV dramas usually depict autopsy work on bizarre murder cases. But of the deceased who came to Baker's office last year, only 46 were homicide victims. Traffic accidents accounted for 104 deaths, non-traffic accidents for 663, and natural causes for 879.

Emotionally, the hardest cases were the 187 suicides last year, he said. Families sometimes are upset and push back against the designation of "suicide" on a loved one's death certificate, he said.

Baker said the single most important piece of evidence in an autopsy is the name of the deceased. Unlike on television, the medical examiner's office doesn't bring a friend or family member in and lift a sheet off a body for identification.

Through a series of pre- and post-mortem photographs, Baker showed how decomposition leaves bodies unrecognizable. Most people are identified through picture identification cards, fingerprints and dental records. "Teeth survive things no other human tissue will survive," Baker said, showing a slide of the matching pre- and post-mortem dental X-rays of the fighter pilot.

DNA gets the publicity, but in real life, it's a time-consuming means of identification that is most helpful during disasters, he said. After 9/11, Baker, who worked at the Pentagon site, said several women on the crashed airliner were identified through tissue that matched that from their Pap smears.

He described one method of getting fingerprints that is not for the squeamish. At a certain time after death, the skin "degloves." An investigator can then slide a gloved hand into the dead skin and successfully roll a set of fingerprints.

Bodies end up without identification only once every three years, Baker said. Cities with larger populations of mentally ill and undocumented residents tend to have a higher number of unidentified bodies.

In cases when the patients can't be identified, tissues and film are collected and saved. Then the body is buried in St. Paul in a plot carefully mapped by Baker's office.