Maryland prosecutors asked an appeals court to deny an appeal by a man convicted of killing his ex-girlfriend whose case became the centerpiece of the popular podcast "Serial."

Prosecutors said Adnan Syed, now 34, 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.

In his most recent appeal, Syed argues he received ineffective counsel because his attorney failed to seek a plea deal even though he asked for one. In their response, state prosecutors say Syed's testimony that he would have taken a deal is not credible, and that his attorney's failure to seek a plea agreement does not constitute deficient counsel.