Cases studies give us the opportunity to apply forensic anthropology techniques on real cases to individual skeletal remains. The purpose of this paper is to describe the last forensic anthropological techniques to analyse human skeletal remains to determine sex, race, stature, age, and to make a positive identification of a teenager who disappeared more than 3 years ago. At the beginning of June, 2017, several human skeletal remains were found under a tree in a little forest of Punta Espinillo location, near the Montevideo City, and later carried to the Central Judicial Morgue to be analyzed by the local forensic anthropologist. The analysis indicated that the victim was a white man of between 15 and 18 years old and about 170 cm tall. The cause of death was by a severe trauma on the left malar region. Based on preliminary evidence it was suspected what the victim might be John Doe, a teenager who disappeared more than 3 years ago when he was 16 years old. Therefore, it is a cold case now opened. Based in actual evidences and the confession of one of the perpetrator it knows that he was murdered by him and his friends of the New Communist Party and later left him unburied on the ground of the forest, where his body was attacked by several depredator animals. Certainly the examination of the remains revealed that the skull had a hard injury on the left malar bone who broken it. A DNA analysis was made by a later identification based on the anthropological data approved by the forensic anthropology studies. Therefore, this case shows how Forensic Anthropology techniques can be successfully used in medicolegal investigations linked with cold cases of more than 3 years ago.