Several families filed formal complaints Thursday against Dr. Charles Siebert, the Bay County medical examiner under fire following the smothering death of boot camp inmate Martin Lee Anderson.

Siebert originally ruled the teen died of natural causes. An independent autopsy found the boy had been smothered by guards at the Bay County boot camp.

Michaela Mahoney said Siebert concluded her son was a suicide victim. She believes he was actually shot by a drunk off-duty cop, and Siebert helped cover it up.

"I think he probably just goes along with whatever law enforcement wants," Mahoney said.

The families all expressed support for the parents of Anderson. They said Siebert makes a practice of siding with police over the truth.

The Anderson case brought back angry memories for John Nieson.

Siebert had reviewed his brother's case from the 1970s and concluded Michael Neison died in a car crash. But the family said evidence pointed to a police beating.

Nieson said he doesn't want Martin Anderson’s parents to go through his pain.

"Don’t make them wait 29 years to get justice. Me and my mom are still waiting," he said.

Mary Terry lost her husband and daughter in a tornado. Siebert did both autopsies, which were littered with mistakes.

"Either he don’t know what he’s doing at all, or there was no autopsy performed, and it causes me and my daughter’s only child to have nightmares," she said.

Siebert stands by his findings in the Anderson case. Now he'll have to justify them to the county Medical Examiner's Board.

Siebert issued the following statement in response to Thursday's formal complaints:

"Filing baseless complaints against me is completely unwarranted. As I have explained numerous times, I am an impartial medical professional who issues unbiased conclusions based on medical and forensic evidence of the case. My medical opinion may not be popular, but it is my job to issue conclusions rooted in scientific fact."