A Baltimore man will remain behind bars for the 1999 murder of his former high school girlfriend after the U.S. Supreme Court on Monday rejected his bid for a new trial in a case that captured public attention after the podcast "Serial" raised questions about his prosecution.The justices turned away an appeal by Adnan Syed, 39, who has been serving a life sentence since 2000 after being convicted in the strangling death of high school classmate Hae Min Lee. Maryland's highest court in March ruled out a new trial for Syed despite his attorney's failure to properly defend him.Prosecutors said Syed killed the 17-year-old Lee in 1999 in the parking lot of a Best Buy store shortly after school, and then buried her body in a shallow grave later that evening. He was jealous, the state argued, because she had started dating someone else. Lee's body was found three weeks later.There were no eyewitnesses to the murder but one witness said he helped Syed bury the body. A jury in Baltimore convicted Syed of first-degree murder and other charges in 2000.In 2015, a state court reopened the case to allow Syed to argue that his initial defense lawyer had been ineffective because she failed to contact and interview a witness, Asia McClain, who could have provided a potential alibi. McClain had said she remembered speaking with Syed at the school library during the time prosecutors had said Syed killed Lee.A new trial was ordered for Syed after a state intermediate appeals court said the attorney's incompetence resulted in impermissible prejudice to Syed's defense.Syed's case won public attention in 2014 when it was the subject of the "Serial" podcast, produced by public radio station WBEZ Chicago and downloaded tens of millions of times. It has since inspired news articles and a documentary on HBO.Last March, in a closely divided 4-3 ruling, the Maryland Court of Appeals, the state's top court, overturned that decision because the jury could have disregarded prosecutors' timeline for when Lee was killed, but still believed that Syed murdered her.