Maryland’s Court of Special Appeals reversed the first-degree murder conviction of the man arrested in the 2004 shooting of a woman at a motel near the campus, the Associated Press reported Wednesday.

The court wrote that “the unexplained presence of a mystery person” in the room at the College Park Motel, as well as unidentified DNA and fingerprints, gave reason to reverse the conviction. The court argued there was not proof beyond a reasonable doubt that the suspect committed the murder.

Roberto Puerto, 45, of Bethesda, had his charges thrown out after he appealed his conviction.

Puerto argued there was insufficient evidence to prove he murdered his former girlfriend, Iris Gonzales of Washington, or that he used her credit card, another charge for which he was convicted.

Puerto also argued that statements he made after asking for a lawyer should not have been used as evidence.

According to a May 2004 article in The Diamondback, Gonzales was found dead in a room at the motel in April of 2004. She had been gagged, bound and stabbed 56 times.

Puerto was arrested in July of 2004 in connection with the homicide, former Prince George’s Police spokeswoman Cpl. Diane Richardson told The Diamondback in a Feb. 2005 article. Puerto was convicted by a Prince George’s County jury for first-degree murder and faced life in prison for the murder conviction.

The Court of Special Appeals also wrote that “the evidence with regard to the murder conviction supported nothing more than a ‘strong suspicion’ that Puerto may have killed Ms. Gonzales.”

The Associated Press contributed to this report.