Coroners in Northern California are farming out thousands of cases each year to a private firm whose doctors have dissected the wrong body and have given inaccurate testimony that helped send an innocent person to jail.

Doctors with Forensic Medical Group Inc. routinely handle caseloads that leaders in the field of forensic pathology call risky, conducting as many as three autopsies in an hour or nine autopsies in a single shift, an investigation by Frontline, NPR, ProPublica, the Investigative Reporting Program at UC Berkeley, and California Watch has found.

Although some of the firm's doctors have been praised for their skills and professionalism, the Forensic Medical Group also has employed physicians who were fired by public agencies for substandard work. The firm twice hired a doctor with a record of poor performance, who five years after botching a case in Sonoma County and after being found incompetent by the California State Bar, was hired a second time.

The region's justice system has come to rely on the Fairfield-based doctors' group, with more than a dozen counties contracting with the firm to do some or all of their death investigations.

Yet the agencies that hire the company often do not check who is performing the work until problems arise, said Chris Andrian, a Sonoma County defense attorney who twice won the release of clients due to the firm's mistakes. In some cases, errors by Forensic Medical Group made it impossible to hold anyone accountable for suspicious deaths.

"They are not being vetted in terms of their backgrounds, their skills, their ability," Andrian said of the private doctors. "You hire a company, and you take the company as a whole. And you never know what you're getting."

The group's doctors acknowledge they have made mistakes, but say that, overall, they have improved death investigation in the region, sometimes under difficult conditions. They often conduct examinations in facilities that are a far cry from state-of-the-art labs seen on TV and drive 100 miles or more between cases on a single day.

The firm has tripled its client list over the past 15 years, propelled by a need for its services, said Dr. Kelly Arthur-Kenny, one of the practice's owners and a primary provider of autopsies in Sonoma County.

"A lot of cases are getting done," she said. "And people don't have a problem with that."

Officials for the Sonoma County Sheriff's Office, which oversees the morgue's operation, said they are satisfied with the professionalism and experience of the group's doctors and are reviewing renewal of the contract this summer.

But Forensic Medical Group's emergence as the dominant provider of autopsy work in Northern California has drawn attention as emblematic of larger flaws in the U.S. death investigation system.

In California and across the nation, a shortage of forensic pathologists has left coroners and medical examiners overburdened. A 2009 study by the National Academy of Sciences concluded that the country has fewer than half the pecialists it needs to competently investigate suspicious deaths.

Many localities rely on uncertified or minimally trained practitioners and look into only a small fraction of all fatalities. Indeed, without Forensic Medical Group, certain types of deaths would go entirely without scrutiny in some of California's most rural areas.

While most autopsy work in Southern California is done by forensic pathologists on the public payroll, the farther north you travel, the more likely that autopsies are being performed by private doctors who are paid based on the volume of work they handle.

These physicians typically operate without the minimal oversight received by their counterparts at public agencies.

"There's no standard," acknowledged Dr. Arnold Josselson, Forensic Medical Group's vice president, when asked if there were rules governing how the firm's doctors did their work or outside monitors to check it.

Instead, he said, the group polices itself. "If we have a question or a difficult case, we will share it with the group and get other opinions about it," he said.

The firm has little competition and has raised its prices substantially over the past five years, county contracts and autopsy invoices show.

Its five doctors examine about 2,500 bodies a year - more than San Diego County's medical examiner and more than twice as many as the Riverside County coroner, according to county financial and autopsy records.

"You can't do that many cases well," said Dr. John Pless, a National Association of Medical Examiner's director and retired forensic pathology professor at Indiana University. "You just cannot do it, I don't care who you are or what you've got working for you. You're going to miss things, there's no question about it."

Arthur-Kenny was tackling her third Sonoma County case before 1 p.m. on Oct. 9, 2006, when she autopsied one man, mistaking him for another.

Her schedule called for her to examine George M. Farnsworth III, 51, who had died in a car crash that morning. Instead, she removed a different body from the cooler at the Sonoma County morgue: John Gobbi, 73, a dairyman who had died after a long struggle with heart disease, county coroner records show.

A technician alerted her to the mix-up after she left the autopsy table to begin dictating her notes. Arthur acknowledged that, acting in haste, she had skipped over routine checks designed to prevent such confusion.

"The bottom line is that I made a mistake, and I didn't check a toe tag on a decedent," said Arthur-Kenny, in a deposition about the case. "It was the third autopsy that I did of that day, and I approached things out of my usual order."

That she was working at a swift pace was no surprise.

The firm, which now has five doctors, does all autopsy work for Sonoma, Colusa, Contra Costa, Sutter and Yolo counties. Forensic Medical Group also provides a share of services to nine other counties, including Lake, Marin, Napa and Humboldt, covering a sprawling 21,000-square-mile territory that stretches to Merced.

Forensic Medical Group's doctors handle more than 300 cases annually; several of its practitioners have autopsied more than 400 bodies a year. Experts recommend no more than 250 a year and argue that examining upwards of 325 leads to exhaustion and a higher incidence of errors.

The firm charges up to $1,250 per autopsy and $600 for external examinations, which involve no cutting. It collects additional fees for travel time, court testimony and responding to death scenes.

The firm has won a reputation for its willingness to take on even the most daunting assignments. In 2008, when Merced County's in-house forensic pathologist quit and bodies began to back up, most of the firm's doctors traveled to Merced's morgue and performed 21 autopsies in a single day.

Josselson, the firm's vice president, said that "most of the cases are straightforward" and that natural deaths require little examination time.

Each day, sometimes even on weekends, the firm's office manager calls Josselson at 7 a.m. with the latest cases. He divvies them up, dispatching doctors to sites that can be hundreds of miles apart, invoices show.

On a day in March 2009, one doctor in the firm conducted two autopsies in Sutter County and then drove 100 miles south to San Joaquin County for three more.

Dr. Brian Peterson, who was the company's longtime president before becoming the chief medical examiner for Milwaukee in 2007, said his work schedule with Forensic Medical Group was daunting at times.

"I can remember one time driving up to Humboldt County, and that was a five-hour drive, to do three autopsies including an infant and drive back the same day to be at work the next morning," Peterson said. "It was wear and tear."

While some of Forensic Medical Group's doctors are held in high regard, several were hired despite troubling track records or a lack of basic qualifications.

One of the firm's most prolific practitioners, Dr. Ikechi Ogan, is not certified as a forensic pathologist by the American Board of Pathology, a measure of basic competence in the field.

From 2007 through 2009, records show, Ogan had performed dozens of autopsies for counties whose contracts specified that Forensic Medical Group send only certified forensic pathologists to do its work. Ogan, who did not respond to requests for comment, has performed some of his autopsy work in Sonoma County. The doctor completed a year of specialized training in Detroit's medical examiner office 12 years ago.

The firm also has hired doctors who have failed at other autopsy jobs, including a high-profile Sonoma County case involving Dr. Thomas Gill.

The murder charge against Petaluma dentist Louis Pelfini for strangling his wife in her bathtub, based on Gill's investigation, was dismissed in 2001. Pelfini's defense revealed that Gill had missed key evidence in the Sonoma County case and that he had been coached by prosecutors to downplay his past.

The firm replaced him in 2002 with Dr. George Bolduc who came with baggage, too. During a stint at the Orange County Sheriff-Coroner's Office, he allegedly based his findings in a homicide case on a police report rather than medical evidence. After losing that job, Bolduc worked at Kinko's and a Safeway. He also delivered newspapers and was a census taker before Forensic Medical Group hired him.

Bolduc stayed at the firm less than a year, joining a different company in Merced after Sonoma County officials raised concerns about his past.

Forensic Medical Group subsequently rehired Gill in 2007, even though Sonoma County would not allow him to conduct autopsies or testify in court. The company finally cut ties with Gill last December after a third county refused to work with him.

Errors by Forensic Medical Group in yet another Sonoma County case helped put Corbin Easterling behind bars for 18 months, charged with a murder he did not commit.

Easterling's wife, Jennifer, drowned in San Pablo Bay's frigid water during the pre-dawn hours of Oct. 12, 2004. Dr. Gregory Reiber, now president of Forensic Medical Group, conducted her autopsy two days later and concluded that she drowned as a result of being suffocated. Coroner's officials listed her death as a homicide, theorizing that her husband had pushed her head under water.

Corbin Easterling's defense team argued that Jennifer Easterling had drowned after passing out from hypothermia. Forensic Medical Group changed its ruling in June 2006, concluding that her had been an accident. Prosecutors dropped the charges against Corbin Easterling, freeing him after 18 months in jail.

Reiber did not respond to repeated interview requests. In a written statement, the firm acknowledged that death scene information would have led him to a different conclusion.

"Difficult cases may have multiple seemingly contrary conclusions, none of which is necessarily wrong," the firm wrote. "As forensic pathologists we are charged with determining the cause of death to the best of our collective ability given the information available, our training and experience."

Corbin Easterling struggled after his release. He overdosed on methamphetamine 11 months later.

"It was so horrible," Richard Jevarian, Jennifer Easterling's father, said of the case's effect on the family. "This makes or breaks the lives of anyone who's involved with this."

California Watch is a project of the nonprofit, independent Center for Investigative Reporting. Lowell Bergman of the Investigative Reporting Program at UC Berkeley contributed to this report.