TROY, Mo. (AP) — A former Missouri deputy who investigated a murder case that became the subject of an NBC show starring Renee Zellweger is now accused of harassing and stalking a detective who was investigating him for potential misconduct.

Mike Merkel, 42, was charged Tuesday and accused of photographing and sending threatening messages to the detective, the St. Louis Post-Dispatch reported.

Merkel was among the Lincoln County Sheriff's Office detectives who initially interviewed Pamela Hupp after Hupp's friend, Elizabeth “Betsy” Faria was stabbed to death in 2011. The investigation resulted in a 2013 murder conviction for Faria's husband, Russell Faria. He was later acquitted and Hupp was charged — a move that resulted in scrutiny of the initial investigation.

The case drew national attention and was the subject of “The Thing About Pam," which ran on NBC earlier this year.

Court records show that in addition to Merkel, his wife Becky and his brother Kevin Merkel — a Drug Enforcement Administration agent — also were charged with first-degree harassment and second-degree stalking of a law enforcement officer. It was not immediately clear whether they have attorneys who could comment.

Russell Faria served more than three years behind bars before being acquitted at his second trial in 2015.

Scrutiny of the botched case intensified in 2016 when Hupp fatally shot Louis Gumpenberger, 33, in her O’Fallon, Missouri, home. Hupp claimed Gumpenberger had tried to kidnap her at knifepoint, but her story quickly unraveled. She was sentenced to life in prison.

Wood, who was elected in 2018, charged Hupp in June 2021 with first-degree murder in Betsy Faria’s death. At the same time, Wood announced misconduct probes into the original investigations of the Faria case.

Prosecutors allege that Mike and Becky Merkel followed and photographed the Lincoln County detective leading the new investigation while he was at dinner March 14 at a Texas Roadhouse in Wentzville, Missouri. That night, the detective allegedly received texts and photos of himself at the restaurant from a masked number.

“I have video of you drinking and getting into your county car,” one read. “We are watching you closely. You should stop throwing stones at glass houses or yours will come down first and fast.”

Troy police said surveillance footage showed Mike and Becky Merkel taking photographs of the detective’s vehicle the night of the threats. Warrants revealed the texts were sent using a number-masking app from a phone issued by the DEA to Kevin Merkel, according to court documents.

“We take this seriously because I’m not going to tolerate people blackmailing my investigator,” Wood told the Post-Dispatch. He said his office found no evidence that the detective had any impairment when driving his department vehicle the night of the threats.