BALTIMORE — Maryland’s second-highest court has upheld a judge’s ruling overturning the murder conviction of “Serial” podcast subject Adnan Syed.

The decision remands the case back to Circuit Court, granting Syed a new trial there.

The ruling could be appealed to the Court of Appeals, the state’s highest court, which would mean many more months before Syed finds out whether his conviction will remain or if he will get a new trial.

Maryland Attorney General Brian Frosh’s office said that it is “currently reviewing today’s decision to determine next steps.”

Justin Brown, Syed’s attorney, said he would be having a news conference Thursday afternoon.

In writing the Court of Special Appeals opinion, which was released Thursday at 1 p.m., Chief Judge Patrick L. Woodward wrote that a “deficient performance” by Syed’s attorney during his initial trial — namely, her failure to call a witness named Asia McClain — “prejudiced Syed’s defense.”

Syed was convicted in 2000 and sentenced to life in prison for the killing of his former girlfriend, Woodlawn High School classmate Hae Min Lee, whose body was found in Leakin Park.

Syed maintained his innocence, and in 2014 his case attracted international attention when it was featured on the “Serial” podcast, which was downloaded millions of times and prompted legions of listeners to scrutinize the case online.

Syed was granted a post-conviction hearing in February 2016, during which his new attorneys argued that his original counsel had failed to call an alibi witness. They also questioned the reliability of cellphone evidence used to place Syed at the spot where Lee’s body was found.

Four months later, retired Judge Martin Welch, who had denied Syed’s previous request for a new trial, vacated his conviction and ordered a new trial.

The judge said questions about the cellphone tower evidence should have been raised by Syed’s original team.

The state appealed a lower court judge’s ruling last year that vacated Syed’s conviction and ordered a new trial. Syed’s attorneys then filed a separate conditional appeal, asking the court to look at the alibi issue.

In the opinion Thursday, Woodward found that, “there is a reasonable probability that McClain’s alibi testimony would have raised a reasonable doubt in the mind of at least one juror about Syed’s involvement (in) Hae’s murder, and thus ‘the result of the proceedings would have been different.’”

The Court of Special Appeals had considered the case during a hearing last June.

There, judges had focused more on the alibi witness angle, questioning attorneys for Syed and the state attorney general’s office about what weight they should give to Asia McClain Chapman, who claimed to have seen Syed at the Woodlawn library when prosecutors Lee was killed.

“How can you possibly evaluate an alibi witness without speaking to her?” Woodward asked during the state’s presentation by Thiru Vignarajah, a special assistant attorney general.

The judges asked Syed’s current attorney, C. Justin Brown, whether there was any case law that would establish that Gutierrez provided ineffective counsel to Syed because she did not speak to McClain.

Judge Kathryn Grill Graeff asked Brown whether it is a defense attorney’s responsibility to speak to any possible alibi witness — to which Brown said yes.

Graeff dissented with the court’s opinion issued Thursday.