Jason Coleman pleaded guilty to one count of aggravated assault and was sentenced Thursday to three years of probation.
According to Tucson Fire, the incident happened in the 9 a.m. hour May 1 in the 1500 block of West St. Mary's Road, where crews responded to help a man who had reportedly fallen.
A pair of bystanders forcefully offered their own treatment to the victim, and firefighters asked the men to leave the area.
The men left for a short time but returned and made threatening comments. The men were asked to leave again. One of them wielded a machete. When they returned, one of them -- Coleman -- attacked a fire captain.
Police arrested Coleman, who originally faced charges of two counts of aggravated assault on a firefighter.