RIO DE JANEIRO, Brazil – Police arrested a teenager and two others Monday in the shooting death of an American professor, saying the suspects were intoxicated when James Petersen was slain in an Amazon rain forest town. Welison Cornelio de Oliveira, 18, was accused of shooting Petersen, the 51-year-old chairman of the University of Vermont’s anthropology department, a police inspector said Monday.

Inspector Normando Barbosa said the three robbed a restaurant where Petersen and a Brazilian archaeologist were dining Saturday in the town of Iranduba. As they were leaving the restaurant, Oliveira turned and shot Petersen once in the chest.

Police also arrested a man, 23, and a 16-year-old male who were with Oliveira and are searching for two other men.