MANITOWOC, WI - Manitowoc County Sheriff's Lt. Andrew "Andy" Colborn, who was at the center of widespread evidence planting and police misconduct allegations in the Oct. 31, 2005 Teresa Halbach murder investigation against Steven Avery, has retired from the law enforcement profession. Millions of people across the globe are familiar with Colborn and his former mentor, Manitowoc County Sheriff's Lt. Detective James Lenk, from the award-winning Netflix documentary, "Making a Murderer." On Friday, Colborn informed Manitowoc resident Debi Hochstetler that he just retired and was no longer in charge of her son's still-unsolved January 1999 hit-and-run fatality.

Her son, Manitowoc high school student Ricky Hochstetler, was run over and killed by a suspected drunk driver while Ricky was walking home during a snowstorm. The fatality happened around bar-closing time in rural Manitowoc, but it immediately turned into a cold-case at the Manitowoc County Sheriff's Department and there have been long-standing suspicions that the crime and the cover-up involved other members of the Manitowoc County Sheriff's Department. On Saturday, Debi Hochstetler wrote in a Facebook forum dedicated to solving her son's case that she got a text from Colborn the day before. "He said he hasn't heard anything back on the paint chips he sent in to Milwaukee yet. And he wanted to inform me that yesterday was his last day. He is retiring. The case has been turned over to Jason Jost. He said that he was very sorry that he wasn't able to solve the case for me and my family ... I don't know Jason Jost but plan on talking to him in the near future to follow up on those paint chips being analyzed. Will keep you posted."

Saturday's development reported by Patch drew an immediate reaction on social media, particularly on Twitter, including a reaction from Jerry Buting, one of Steven Avery's criminal defense attorneys who was featured in "Making a Murderer" as being a crusader for truth and justice. Colborn's monthly pension will include the standard issue Manitowoc retirement ration. https://t.co/vy4QTE5N9M pic.twitter.com/qDYP0TtoAl

— Jerome Buting (@JButing) February 4, 2018 Others also reacted on social media with glee.

Like rats deserting a sinking ship. Another one bites the dust...

— Debra Sullivan (@Deboryn123) February 3, 2018 Great piece from @johnferak on Colborn and his "retirement". #MakingAMurderer https://t.co/QxNbbOhfxd

— Andy Newton (@AndyNewtonTT) February 3, 2018 Colborn gained world-wide infamy after the December 2015 release of "Making a Murderer"' on Netflix. He and Detective James Lenk, who retired about five years ago, were at the center of evidence planting allegations raised during the 2007 murder trial of defendant Steven Avery by his lawyers Jerry Buting and Dean Strang. The Manitowoc County Sheriff's Department was not supposed to be investigating Steven Avery as a murder suspect because it had a conflict of interest. Avery had a $36 million civil rights lawsuit against the county over his 1985 wrongful conviction for rape, a case that cost him 18 years of his life due to an erroneous conviction caused by Manitowoc County's Sheriff's Department. But that did not prevent the Manitowoc County's Sheriff's Department from taking on the lead role in the evidence collection efforts against Steven Avery on the Avery Salvage Yard property in November 2005, days after Auto Trader magazine photographer Teresa Halbach, 25, vanished the same afternoon she had visited Avery's salvage. The evidence gathering team included Colborn, Lenk and fellow Manitowoc County Detective Dave Remiker and one deputy from neighboring Calumet County.

On Nov. 8, 2005, after Lenk and Colborn were inside their murder suspect's bedroom, a spare key for the victim's RAV4 was found on the carpet next to Avery's bed. The key was later determined to contain Avery's DNA. Only weeks before Halbach vanished, Colborn was questioned by civil rights lawyers as part of Avery's $36 million lawsuit against Manitowoc County. Teresa Halbach's regular set of car keys, as well as her house keys, have never been found. Colborn and Lenk and a sergeant from Calumet County had previously spent several hours inside of the Avery bedroom, days earlier, and the spare key was not on the floor.

Colborn, who turns 59 next month, remains at the heart of another mystery in the Teresa Halbach murder investigation. He was the Manitowoc sheriff's deputy who called into the dispatch from a cell phone, asking the dispatcher to confirm the license plates for Halbach's blue-green Toyota RAV4. Days later, the RAV4, minus its license plates, was found on the far edge of Avery's 4,000-vehicle salvage yard. Avery's post-conviction lawyer Kathleen Zellner suspects that Colborn found the car and had a direct role in moving it to the Avery salvage yard property to solidify Manitowoc County's case against their murder suspect.

Colborn was also involved in a controversy surrounding Steven Avery's 1985 wrongful conviction for a brutal rape committed by a dangerous Manitowoc sexual predator named Gregory Allen. In 1995, when Colborn worked inside the Manitowoc County Jail, a detective in Green Bay called to explain that an inmate had confessed to committing a rape in Manitowoc County. However, Colborn did not vigorously pursue the matter at the time. The end result of Colborn's inaction was that Avery remained wrongfully imprisoned for another eight years. He was finally exonerated through DNA testing in September 2003.

Colborn biography: