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Starr County Special Crimes Unit announced it began investigating cold cases last year, including the 20-year-old unsolved murder of 45-year-old Dario Salmon.

Investigators said Salmon was stabbed to death in his front yard in 2001, adding that the defendant in the case, Luis Carlos Marez, is currently serving a sentence in the Texas Department of Corrections.

Commander Robert Caples said Marez agreed to talk to police about Salmon's murder.

Marez told police another man, Joe Bazan, thought Salmon had gotten his girlfriend hooked on drugs, Caples said.

Investigators said an additional person is involved in the case, but their identity and role have not been released.