The convicted killer at the center of a popular podcast is making his case that an appeals court should toss his conviction on grounds that his lawyer failed to interview an alibi witness and never inquired about the possibility of a plea deal.

An attorney for Adnan Syed, now 34, filed a brief Monday with the Maryland Court of Special Appeals, which has agreed to take up Syed's case.

Syed was the centerpiece of "Serial," a wildly popular podcast that raised questions about the integrity of the case and Syed's guilt.

Prosecutors say Syed strangled his former girlfriend in 1999 after the two high school students broke up and she began dating someone else. Syed has been in prison since 2000, serving a life sentence.