BALTIMORE - Maryland prosecutors are asking a Baltimore judge not to grant a new trial for the man convicted in a murder case re-examined by the popular "Serial" podcast. They argue that Adnan Syed wasn't convicted because of ineffective counsel or faulty evidence, but because "the evidence was overwhelming, and because he did it."

Deputy Attorney General Thiru Vignarajah launched into his closing arguments Tuesday afternoon after four days of testimony.

Syed, now 35, is serving a life sentence after being convicted of murder in the 1999 strangling death of his ex-girlfriend, Hae Min Lee.

His lawyers argued that he deserves a new trial because his trial attorney did not contact an alibi witness who said she saw Syed in a public library during the time Lee was killed, and because prosecutors presented cell tower data to jurors without a cover sheet warning that information about incoming calls was unreliable.

Prosecutors said the data linked Syed to the site where Lee's body was buried on the night she was killed.

Vignarajah acknowledged the intense media attention generated by the podcast, which attracted millions of listeners who became fascinated with the murder case.

He said "this is not a popular position, but the state's role is to do justice."

Vignarajah will continue his arguments after a brief lunchbreak.