Dateline: Justice for Meghan, which originally aired on NBC in November 2023, revisited the brutal murder case of 16-year-old Meghan Landowski. In April 2008, the high school student and former dance student from Portsmouth, Virginia, was found gagged, s*xually assaulted and stabbed more than 40 times in her home.Meghan's stepfather, Chris Shortt, initially requested an NCIS investigation, believing that Meghan was killed by his fellow Navy Corps friend, Robert Hicke, who had previously assaulted her. However, Hicke was cleared after his DNA did not match the one obtained from the crime scene.As featured in Justice for Meghan, after six months of investigation, the authorities shifted their focus to Robert Lee Barnes, a 17-year-old violin virtuoso and Meghan's classmate. After witness accounts, DNA testing and Barnes' confession, he was sentenced to 42 years in prison.This is how Robert Barnes attempted to undo his guilty plea and what happened afterwards.Dateline: Justice for Meghan - Revisiting Robert Barnes' confession in the Meghan Landowski caseAfter six months, Meghan Landowski's case saw a breakthrough when a bus driver provided an important tip to her mother, Angie Shortt. She shared the tip with CBS News:"So they were both in the performing arts program. …He played the violin in the orchestra and she was a dancer. …Robert Barnes … would come over two, three times a week to catch the bus with Meghan. …They didn't hang out together, anything like that. It was just friends. …I thought to myself, "He's harmless."As featured in Justice for Meghan, this gave the case a new direction and the investigators shifted their attention to Robert Barnes. Additionally, witness accounts from Meghan's dance instructor suggested that Robert knew a lot about her whereabouts and lifestyle and was likely near her during the time of her death.Despite many possible leads, Justice for Meghan revealed that the investigators followed Robert Barnes' lead, which eventually proved right. While Barnes tried to falsify his DNA by swapping his chewing gum sample with a woman, his DNA matched the one found at the crime scene, proving that he had killed his classmate. Additionally, the investigators connected a footprint from the crime scene to Barnes' Nike tennis shoes, proving that he was present on the premises during Meghan Landowski's murder.After a lengthy interrogation, Robert Barnes confessed to Meghan Landowski's murder and pleaded guilty to charges of attempted r*pe, first-degree murder, aggravated s*xual battery, statutory burglary, and abduction. The confession, made to avoid a long and tedious jury trial, was eventually accepted and Robert Barnes' plea deal led to his sentencing.In 2009, Robert Barnes was sentenced to 148 years in prison with all but 42 years suspended.Justice for Meghan - Robert Barnes tried to withdraw his guilty plea in 2012According to The Virginian-Pilot, Robert Barnes tried to withdraw his guilty plea in April 2012, claiming that he was unlawfully incarcerated. Barnes filed a petition for a writ of habeas corpus without an attorney and claimed his defense lawyers had persuaded him to enter the guilty plea in 2009. Through his 2012 plea, Barnes sought to withdraw his original guilty plea and asserted his innocence in Meghan Landowski's murder.However, Portsmouth Circuit Judge Dean W. Sword Jr. denied and dismissed Robert Barnes' petition in June 2012, ruling against his request to erase the plea agreement.Justice for Meghan: Where is her killer now?As of 2024, Robert Barnes was incarcerated at the Pocahontas State Correctional Center, according to the Virginia Department of Corrections and will be released in 2045.While Robert Barnes never revealed the motive behind Meghan's murder, Detective Sgt. McDaniel, who interviewed him before his guilty plea, presented a theory:"He had a romantic interest in her and she at some point rejected him prior to this... He wanted to talk about what he did, but at the same time he wanted to make it look like someone else was there."You can stream Dateline: Justice for Meghan on NBC.For the latest scoops on your favorite TV shows and movies, follow SoapCentral.