Fond du Lac Police Chief William Lamb said the officer was following the suspect’s vehicle at about 5.30pm on Tuesday when the incident occurred.
“Both the trooper and the suspect were killed in the exchange of gunfire,” he said.
There are no further details about the trooper or the suspect.
The Wisconsin Department of Justice said investigations are taking place into several crimes that occurred on Tuesday in Marinette County and in Fond du Lac, including the death of the trooper.
“We cannot confirm at this time definitively how these crimes fit together but investigators are working to provide an accurate timeline of events,” a spokesman said.
Marinette County Sheriff’s office issued a statement saying authorities had been notified about 1:43 p.m. of a bank robbery in the village of Wausaukee.
It said a man had fired one round from a handgun and robbed the bank.
It went on to say it later learned the suspect had exchanged gunfire with a state trooper in Fond du Lac.
Meanwhile, in San Jose, California, another officer was shot and killed while responding to a call of a suicidal man.
Michael Johnson, a 14-year force veteran, received a fatal gunshot wound as he and colleagues approached the suspect’s apartment on Tuesday night.
The attacker, 57-year-old Scott Dunham, was found dead with a gunshot wound, though it is unclear if it was self-inflicted or from officers who returned fire.