The FBI says an Arizona man was armed with a knife when he was fatally shot by a National Park Service ranger at a national monument.
Authorities say 43-year-old Venson Yazzie was killed in an area overlooking ruins at Canyon de Chelly in Chinle.
It's still unclear what led to the shooting Friday afternoon.
The FBI said Wednesday it is investigating an assault on a federal officer but won't elaborate.
Park Service spokeswoman Vanessa Lacayo says the ranger is on paid administrative leave and won't be identified unless he's found guilty of a crime.
A local tour guide, Adam Teller, says Yazzie was a vendor who sold rock art to tourists at the monument.
Canyon de Chelly, on the Navajo Nation, has thousands of ruins, carvings and paintings on stone.