Adnan Syed, the subject of the first season of 2014 podcast phenomenon Serial, took a giant step closer to freedom on Thursday after an appellate court ruling upheld a previous circuit court ruling vacating his conviction of life sentence for murder and granting him a new trial.

There are several other complicated steps to go, however, before Syed can walk free — and that’s not a guarantee.

Syed was a high school student when he was convicted of the 1999 murder of Hae Min Lee, his high school classmate and ex-girlfriend. Syed’s case fell into obscurity until Serial re-investigated it, dredging up a litany of intricate new evidence casting reasonable doubt on the prosecution’s case while turning Syed and everyone involved in the podcast into minor celebrities.

A crucial piece of the circuit court’s decision to vacate Syed’s conviction concerned vital evidence first uncovered through Serial. The appellate court stood behind this ruling on appeal to consider closely one piece of evidence in particular. One of Syed’s classmates, Asia McClain, had written his defense attorney in 1999 to provide him with an alibi for the afternoon Lee’s murder occurred. But that letter was never followed up on; McClain’s testimony was never evaluated by Syed’s defense and never made it into the trial.

The Court of Special Appeals found that this oversight was prejudicial for the defense — a stance that, interestingly, overrides the lower court, which based its decision not on the omission of McClain’s testimony, but rather on the failure of Syed’s lawyers to thoroughly cross-examine the state’s cellphone tower expert about the reliability of data that helped place Syed at the scene of the crime. The appeals court decision basically inverts that reasoning, affirming the lower court’s decision on the grounds of the McClain testimony but not the cellphone tower.

The short and sweet: we won on the @AsiaRChapman issue (Lord am I happy I found you and you gave me that affidavit Asia), lost on the cell tower/plea issue (not on merits but for procedural reasons). Here is the part that we have waited for 19 years: pic.twitter.com/P7RVzIlMw4 — rabia O'chaudry (@rabiasquared) March 29, 2018

In a 138-page opinion for the court, Chief Judge Patrick L. Woodward declared that “Syed’s Sixth Amendment right to effective assistance of counsel was violated by trial counsel’s failure to investigate a potential alibi witness,” and that “McClain’s testimony would have directly contradicted the State’s theory of the case by placing Syed at the Woodlawn Public Library at the exact time the State theorized that Syed murdered Hae ... if McClain’s testimony had been presented to the jury, it would have ‘alter[ed] the entire evidentiary picture.’”

Though the new ruling is promising for Syed — who received his initial vacated sentence on his very last appeal — he’s not out of the woods yet.

For starters, the appeals court ruling came with a dissenting opinion by Judge Kathryn Grill Graeff, who noted that the lower court had found several reasons for holding that Syed’s original defense attorney, Cristina Gutierrez (who died in 2004), had acted reasonably by not pursuing McClain’s alibi. This dissent could embolden the state to pursue an appeal to the higher appellate court, which would then rehear arguments made at the lower appellate and circuit courts.

If the state appeals to the higher court, the court could overturn the earlier decisions and uphold Syed’s conviction. If the higher court also finds cause for a new trial, then the state would be back where it is today: facing the possibility of retrying Syed under much more injurious circumstances.

Whereas Syed was an unknown high school student in 1999, today his is one of the most famous murder cases in the country, with a prestigious pro bono defense team. What’s more, he now has an alibi for the exact time in which the prosecution alleged he murdered Lee. Under these circumstances, the state could opt not to retry Syed. (It might even opt to pursue a hunt for other suspects in Lee’s murder.)

The Maryland attorney general’s office told the Baltimore Sun that it was “currently reviewing today’s decision to determine next steps.” Serial fans have been waiting a long time to #FreeAdnan, but they’ll have to wait a little longer.