An autopsy diagram shows where gunshots hit Michael Brown. (Joe Raedle/Getty Images)

In the name of getting to the truth, Michael Brown’s body has undergone three autopsies following his shooting death Aug. 9.

First came the one conducted by the county medical examiner’s office. Then, forensic pathologists Michael Baden and Shawn Parcells flew to Missouri to examine Brown at the request of the teenager’s family.

Amid violent protests, U.S. Attorney General Eric H. Holder Jr. ordered a federal autopsy, which was completed Monday by U.S. military medical examiners. It was the third such examination of the same body in a week’s time.

Is there a value in conducting multiple, consecutive examinations on the same body?

Although some experts say that experienced forensic pathologists should have no trouble conducting an accurate second — or even third — autopsy, it’s unlikely that the subsequent examinations would uncover substantial differences in fact.

But the body being examined would be altered significantly: David Fowler, chief medical examiner for the state of Maryland, told The Post that the process of conducting the first exam would dramatically alter the appearance of the body, including its organs. Still, Fowler said, those changes would present only minor challenges to experienced, qualified pathologists conducting the second or third autopsies.

To start with, a full autopsy involves the removal and scrutiny of the individual organs. The first pathologist would detach the organs from their places in the body cavity, and from each other. Each organ is dissected and sliced over the course of the examination. The pathologist takes samples as needed. The second pathologist would have to start with the organs already removed, dissected and examined.

By the third autopsy, the pathologist would start with a “a bag of finely-cut, possibly decomposing tissue,” University of Arizona forensic pathologist Veena Singh wrote in an e-mail. “Only the first pathologist is able to see everything as it was at the time of death,” added Singh, who works for the Pima County medical examiner’s office.

But it’s “usually not a big problem for a good pathologist” to complete an accurate autopsy under those more complicated circumstances, Fowler said.

That’s not the only difference in a body undergoing multiple examinations.

“Sometimes in between the first and second autopsy, the body may be embalmed,” Fowler said, adding that embalming “can sometimes alter some of the features externally to a minor degree.”

With each subsequent autopsy, the pathologist must sort through those artifacts of previous exams. Even then, “the external findings (number and location of bullet wounds, for example) should still be the same,” Singh explained.

The difficulty of conducting a second autopsy also depends on the specific case. Some tests and procedures, for practical reasons, only happen once.

In a case like Brown’s, the medical examiner would be concerned with gunshot wounds, along with any signs of a struggle. Fowler said that the evidence on and in the body usually remains intact between the first and the second autopsies.

The external gunshot wounds, for instance, would still be present, appearing “exactly the same” for the second and third examiners, he said. And signs of struggle are usually the same.  “With a one-off event, there aren’t normally substantial differences,” Fowler added. 

Other evaluations are more complicated. Lawrence Koblinsky, a John Jay College of Criminal Justice professor with expertise in forensic science, said that in some cases, the removal of organs might make it impossible to perform a second investigation of bullet trajectory, despite the clarity of the entrance and exit wounds.

However, there are several tools — X-rays, for example — available to experts, in addition to a second (or third) physical examination. The same goes for looking for signs of a physical altercation: Officials investigating a death like Brown’s would not rely entirely on the autopsy to piece together the moments before death, Koblinsky added. 

Singh gave a few other examples of procedures that might only happen once. Sometimes, a pathologist has to cut through a bone in order to remove a bullet or examine an injury. Other gunshot cases require the pathologist to retain a portion of bone in order to de-calcify the sample and retrieve a bullet.

The same goes for a toxicology; in general, Fowler said, samples are collected just once for routine tests. The first pathologist would remove and measure any body fluids as part of the examination. However, it’s likely that there would be preserved samples remaining after the first test, should a second be required.

There are some cases, though, where the second autopsy might be much more difficult. Pathologists would have a more complicated second examination with possible child abuse cases, Fowler said, because of the way pathologists examine bite marks and other signs of sustained abuse over time. 

Despite these challenges, the Brown autopsies should present three very similar — or even identical — sets of facts. But that expected uniformity wouldn’t extend to the conclusions drawn by the pathologists.

“If you’ve got decently qualified pathologists, all of the observations should be identical,” Fowler said, but he noted that, as in most cases involving experienced professionals, the exact same observations can lead to different opinions. 

“There are situations where there are differences of opinion. No doubt about that,” Koblinsky added. But, he said, he doubted there would be a significant difference between the autopsies in Brown’s case. 

“If you gave 10 pathologists the same material they’d come to slightly different conclusions,” Fowler said. And that’s normal, he said. He compared it to a routine check-up for a living human being: “The basic observations are rather like 10 doctors taking a blood pressure,” Fowler explained. “Some might say ‘your blood pressure is a little high, I think you need treatment,'” while another might say that the same patient’s blood pressure, measured at the same level, requires no treatment at all.

But dramatic differences in opinion among experienced pathologists is highly unusual.

So, too, are multiple, separate autopsies upon the same body. “In the six years I have been here in Pima County,” Singh wrote, “I can think of only a few cases where it has happened. And those have been a second autopsy only, not multiples.”

Fowler’s department examines 4,000 bodies a year. He remembers only one case in his time at the Maryland medical examiner’s office where a second autopsy was performed upon a body, sometime in the 1990s, he said.

In the past 10 years, he remembers a single case during which a victim’s family requested a separate medical examiner be present for the autopsy. In such cases, Fowler said, he is happy to honor that request:  “Quite frankly, I love doing it that way because it strengthens our credibility,” he said.  

But families seeking a second autopsy often face substantial bills for the procedure, sometimes including the disinterment of the body in an older case, Kobilinsky said. Still, “when there are criminal matters where families don’t trust the police,” Koblinsky said, some families think it’s worth the cost. 

That brings up another variable in the process of conducting an autopsy: who pays the salary of the pathologist doing the job, and whether that pathologist works independently.

Fowler, whose department is an independent operation within the state’s department of health and mental hygiene, noted that there’s a wide range of systems in place across the country.

Sometimes, an elected coroner’s office is in charge of hiring pathologists to perform a county’s autopsies. Sometimes, that’s the job of a law enforcement department, which can sometimes lead to the perception of bias. In St. Louis County, Michael Brown’s autopsy went to the county medical examiner’s office, which falls under the jurisdiction of the county’s health department.

“From an autopsy standpoint, I actually think the [county] exam was handled appropriately so far,” Singh wrote, “in the sense that the examination was done by an actual forensic pathologist in a medical examiner’s office.” A system like St. Louis County’s  is similar to the one Fowler works in — and it’s what he prefers. “If we can do our function independently,” Fowler said, “then the outcome is the truth.”

[This post has been updated.]