A federal jury has found an American Samoa man guilty of assaulting a federal employee with a machete during an incident in which he cut off part of the official’s left ear.

Prosecutors said the jury in the U.S. District Court for Hawaii convicted Simeti Lualemana on Wednesday after a five-day trial and less than one hour of deliberation. The 67-year-old faces up to 20 years in prison. 

Federal officials say Mark Cunningham, station chief for the National Oceanic and Atmospheric Administration, was attacked last March while taking pictures of a house Lualemana was building on administration-controlled land in the U.S. territory. 

Cunningham had previously told Lualemana the house couldn’t be built there.

The FBI says Cunningham suffered a cut nearly 6 inches long to his neck.