luis andres cuyun was riding in a car when two suspected mara salvatrucha members opened fired on him and his driver , who was injured in the attack .
a salvadoran man arrested for alleged involvement in the shooting later told authorities that he had come to the country specifically to kill cuyun as he made his way to work on friday .
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luis andres cuyun , 30 , the director of a jail for young gang members in guatemala city , was killed .