Adnan Syed was released from prison on Monday.  A year-long investigation revealed new evidence, about the possible involvement of two other suspects in the 1999 death of student Hae Min Lee.

Lee, 18 at the time of the incident, was discovered buried in a Baltimore park. She was strangled to death. Syed, Lee’s ex-boyfriend, was arrested and charged with her murder at the age of 17.

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He was later sentenced to life in prison in 2000 after being convicted of murder, robbery, kidnapping, and false imprisonment.

The case gained international attention as a result of the 2014 Serial podcast by Sarah Koenig. 

The names of the two alternate suspects in the case were not mentioned in the court filing on Wednesday, citing an ongoing investigation. According to the prosecutors, both the people involved were both known to the initial 1999 murder investigation of the case. 

Both suspects have a criminal history, with one convicted of a car attack on a woman and the other of serial rape and sexual assault. New court documents reveal that one of the suspects had threatened to kill Lee around that time. He said that “he would make Lee disappear. He would kill her,” the documents said.

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Ronald Lee Moore, a career criminal and accused murderer from Baltimore, was named as a suspect in Lee’s slaying by journalist Sarah Koenig in Serial.

Moore, who committed suicide in a Louisiana prison in 2008, had previously been convicted of burglary and was also suspected of a number of other burglaries, unsolved sexual assaults, and murders throughout Maryland.

He was released from prison just ten days before Lee went missing and died. He was initially investigated, but DNA found at the crime scene did not match him. Moore was also named as a suspect in the 1999 slaying of Annelise Hyang Suk Lee in Baltimore in 2013.