The man at the center of the most popular podcast ever -- Serial -- will appear in a Baltimore City courtroom in the morning.

Adnan Syed has already served more than 15 years of a life sentence, for the murder of his ex-girlfriend Hae Min Lee. They were classmates at Woodlawn High School in the late 1990s.

Ever since Lee was strangled back in 1999, Syed's family and friends have maintained that he's innocent.

At his post-conviction hearing that starts Wednesday, his attorneys will try to prove he deserves a new trial.

A key witness will be Asia McClain -- who you may have heard in the podcast.

“It's what we've been waiting for and we're hoping this will be the game changer,” said Rabia Chaudry, a family friend who has advocated for Syed since his arrest.

McClain says she was with Syed in the library near Woodlawn High School at the time the state says the murder happened.

“The state is saying that Hae was killed in that time,” Chaudry said. “Well, Asia from day one has been maintaining that she was with him.”

But McClain was never called to testify at his trial; Syed's supporters say that's a sign his lawyer failed him.

Both sides will also call experts to testify about whether cell tower technology -- which placed Syed at the crime scene -- was reliable back in 1999.

Inside a mosque in Howard County on Tuesday night, Syed's brother thanked his friends and family -- and people around the world who heard Serial and have been sending letters of support.

“For him to have been alone for so long and then to have all these people caring it was overwhelming for him,” Yusuf Syed said.

Adnan Syed is now 35 years old. He's been transported to a state prison in Jessup for the hearing, which is scheduled to last through the rest of this week.

“I think this is one of our best shots ever. but we've thought that before too, and it didn't work out so you never know,” Chaudry said.

At this point in the case, he prosecution is represented by the Maryland Attorney General's office. We reached out to that office Tuesday night; a spokesman declined to comment.

The hearing is scheduled to start Wednesday morning at 9:30 a.m. at Courthouse East.

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