SOMERVILLE — A longtime investigator and criminal forensics expert continues to cast doubt on the competency of the Somerset County Prosecutor’s Office, which has faced public scrutiny for its handling of several high-profile investigations.

Detective Jeffrey Scozzafava says the office’s unit in charge of investigating crime scenes and suspected arsons has mislead prosecutors and the public, and used “phony and non-existent” techniques to examine evidence, according to his whistleblower lawsuit that he filed October in Superior Court.

Scozzafava’s lawsuit says the office appointed people with no experience or little training to be in charge of the Forensics Unit. After he complained, Scozzafava says he was penalized by being transferred to a unit that apprehends fugitives — a less desirable, more dangerous assignment that doesn’t make use of his 20 years of expertise. Scozzafava is the president of the International Association of Bloodstain Pattern Analysts.

This is Scozzafava’s second lawsuit against his bosses. In 2016, he filed similar a whistleblower lawsuit that said investigators botched the probe into the deaths of Cooper Health System CEO John Sheridan and his wife, Joyce, by throwing out evidence.

The lawsuit fueled the Sheridan family’s criticism of the office’s investigation into their parents’ bizarre deaths. Investigators quickly concluded in 2014 that Sheridan stabbed his wife to death in their bedroom, then set the room on fire and stabbed himself several times in his neck and chest.

But the couple’s sons doubted that version, pointing to the fact that the weapon that caused John Sheridan’s wounds was never recovered, as well as other mistakes in the investigation’s findings.

John Sheridan, president and Chief Executive Officer of The Cooper Health System in 2013 (AP Photo/Mel Evans, File)

The prominent couple’s sons enlisted several former governors to lobby the state to reopen the investigation.

Last year, Gov. Chris Christie appointed a new prosecutor in Somerset County, later saying that he had “lost confidence” in Prosecutor Geoffrey Soriano.

In January, the State Medical Examiner’s Office changed John Sheridan’s manner of death from “suicide” to “undetermined.”

The office has been criticized for its handling of other cases, as well. The widow of former Somerville fire chief George Kavanaugh, who was killed in a hit-and-run outside a firehouse in March 2015, which remains an unsolved mystery, told the Philadelphia Inquirer that year that she doesn't think "they know how to solve a crime" and that she suspected "a big cover-up here."

In January, a Superior Court judge dismissed Scozzafava’s lawsuit because he could not show that he had suffered a negative job action under the state’s whistleblower-protecting Conscientious Employee Protection Act.

Scozzafava is appealing that ruling while proceeding with this new case, which addresses further retaliation since his previous lawsuit.

His latest lawsuit does not mention the Sheridan case, and does not cite examples of how investigators mislead the public.

Scozzafava is represented by David Zatuchni, of Lambertville, who did not immediately return a request for comment Tuesday.

A spokesman for the prosecutor did not immediately return a request for comment Tuesday.

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