According to the court order, obtained by People, the judge cited "failure to contact a potential alibi witness" as well as failure to disclose evidence that related to cell phone tower data.
"It is finally ordered that Petitioner's request for a new trial is hereby granted," Judge Welch wrote in the order.
The ruling comes after a post-conviction hearing in February in which Syed's legal team presented new evidence, including the testimony of a new alibi witness as well as arguing that his original defence counsel had been negligent.
Syed's brother Yusuf told the Baltimore Sun the family was "feeling great" following this latest development.
"I had a feeling in my heart it was going to happen," he said. "We are just very happy. It's not only a win for us but a win for a lot of people who are stuck in the system because it opened a lot of people's eyes about the justice system."
Syed’s legal team are holding a press conference later today.