(CNN) Baltimore prosecutors filed a motion Wednesday asking for a new trial for Adnan Syed, whose case was the subject of the hugely popular first season of the "Serial" podcast.
A statement from the state attorney's office cited newly discovered evidence.
"After a nearly year-long investigation reviewing the facts of this case, Syed deserves a new trial where he is adequately represented and the latest evidence can be presented," Baltimore City State's Attorney Marilyn Mosby said in the statement.
Syed is serving a life sentence after he was convicted of first-degree murder, robbery, kidnapping and false imprisonment in February 2000 for the slaying of his ex-girlfriend, Hae Min Lee. He has maintained his innocence and has been appealing his convictions for years.
"As stewards of the court, we are obligated to uphold confidence in the integrity of convictions and do our part to correct when this standard has been comprised," Mosby said. "We have spoken with the family of Ms. Hae Min Lee and (they) fully understand that the person responsible for this heinous crime must be held accountable."
The re-investigation of the case revealed evidence "regarding the possible involvement of two alternative suspects other than Syed," the statement said. "The two suspects may be involved individually or may be involved together."
The state will request that Syed be released on his own recognizance pending the investigation if the motion to vacate his conviction is granted.
"We believe that keeping Mr. Syed detained as we continue to investigate the case with everything that we know now, when we do not have confidence in results of the first trial, would be unjust," Mosby said.
Attorneys for Syed filed a motion supporting the state's request to vacate his conviction, according to his legal team at the Maryland Office of the Public Defender and the University of Baltimore Innocence Project Clinic.
"Given the stunning lack of reliable evidence implicating Mr. Syed, coupled with increasing evidence pointing to other suspects, this unjust conviction cannot stand," Assistant Public Defender Erica Suter, Syed's attorney and director of the Innocence Project Clinic, said in a statement.
Maryland public defender Natasha Dartigue in a news release called the case "a true example of how justice delayed is justice denied. An innocent man spends decades wrongly incarcerated, while any information or evidence that could help identify the actual perpetrator becomes increasingly difficult to pursue."
Adnan and Lee were seniors at Woodlawn High School in Baltimore County in January 1999 when she disappeared. Her strangled body was discovered in a city forest three weeks later.
Mosby said prosecutors are "not asserting, at this time, that Mr. Syed is innocent" but that the state "lacks confidence in the integrity of the conviction" and that Syed should get a new trial.
Syed and prosecutors in March filed a joint motion for post-conviction DNA testing, saying that since the crime occurred more than two decades ago, "DNA testing has changed and improved drastically."
The March motion asked that the victim's clothing be tested for touch DNA, which was not available at the time of trial. Items now being tested were not previously tested in 2018 -- when the Baltimore City Police Lab tested various items for DNA -- with the exception of the victim's fingernail clippings, Mosby's statement said.
Mosby said the motion to vacate was filed along with Sentencing Review Unit (SRU) Chief Becky Feldman. Syed was a juvenile when convicted.
The suspects were known persons at the time of the original investigation "and were not properly ruled out nor disclosed to the defense," according to Mosby's statement.
The state is not disclosing the names of the suspects but said that, according to the trial file, one of them said, "He would make her [Ms. Lee] disappear. He would kill her."
The investigation also revealed that one suspect was convicted of attacking a woman in her vehicle, according to the statement. The second suspect was convicted of engaging in serial rape and sexual assault, the statement said.
Some of the information was available at the time of the trial, the statement said, and some came to light later. It is not clear when these assaults took place.
Lee's car was located "directly behind the house of one of the suspect's family members," the statement said.
Attorneys for Syed brought the case to the attention of the SRU in April of 2021.
Syed's attorneys "identified significant reliability issues regarding the most critical pieces of evidence at trial," Mosby's statement said.
In the 2019 HBO docuseries "The Case Against Adnan Syed," an attorney for Syed said his client's DNA was not found on any of the 12 samples retrieved from the victim's body and car. That testing was not part of the official investigation by authorities. HBO, like CNN, is a unit of Warner Bros. Discovery.
At trial, prosecutors relied on testimony from a friend, Jay Wilds, who said he helped Syed dig a hole for Lee's body. To corroborate his account, prosecutors presented cell phone records and expert witness testimony to place Syed at the site where Lee was buried.