WASHINGTON — (CNN) A Baltimore judge has granted a new trial for Adnan Syed, who was convicted of murder in 2000. Syed’s case was the focus of the first season of the popular “Serial” podcast.

Syed was a senior in high school when he was arrested in 1999 in the killing of his ex-girlfriend Hae Min Lee. In the original case, prosecutors argued that two incoming phone calls made to Syed’s cellphone placed him at the site where Lee’s body was buried.

Syed’s attorney presented a motion saying AT&T, which provided cellular data for Syed’s cellphone, warned prosecutors that incoming calls were not considered reliable for location.

Baltimore Circuit Court Judge Martin Welch said in the order that there was “alleged ineffective assistance for the failure to cross-examine the State’s cell tower expert about the reliability of cell tower location evidence.”

Syed, 35, is currently serving a life sentence.

The “Serial” podcast dug into several puzzles surrounding the case.

Among them is why Asia McClain’s account — she says she was with Syed in the library at the time of the murder — didn’t make it into the defense case.

She says her attempts to relay this potentially crucial evidence to his lawyer fell on deaf ears.

Syed has argued that his trial attorney, Cristina Gutierrez, made a series of missteps on his case, including failure to seek a plea deal and not speaking to McClain, who was an acquaintance of Syed.

McClain filed an affidavit in January indicating she would be willing to testify.

She said an assistant state’s attorney involved in the case had discouraged her from attending Syed’s original post-conviction hearings in 2012.