Wisconsin police managed to get their hands on a man dressed in camouflage clothes and armed with an assault rifle. The man has reportedly walked out of the woods and shoot four people who where near a river getting ready to go swimming. Three of them died of their wounds and a fourth one was wounded, authorities said.

Local authorities deployed on Friday at least 100 law enforcement officers from more than 10 agencies to search the killer gunman described as a middle-age man who had last been seen near the town of Niagara in northern Wisconsin, across the state line from Michigan's Upper Peninsula.

Officers had set up roadblocks at Highway 141 and county Highway N in Niagara and along some rural roads in Niagara as they searched for the gunman. Police personnel also evacuated an unknown number of homes.

The group of people who had gathered near a railroad bridge on the Menominee River to go for a swim contained nine people. The shooter came out of the woods and opened fore at about 5:30 p.m. Thursday, according to Sheriff Jim Kanikula.

Police investigators still don’t know what drove the armed man to shoot the people all of a sudden. However, there was no communication between the shooter and the young people before the shooting started, said the sheriff. The gunman was only 7 to 10 feet away from one victim when he fired, authorities said. Two of the dead bodies were left on the ground about three miles west of Niagara because of fear that the shooter was still in the area.

Police officials said the victims are: Tiffany Pohlson, 17; Anthony Spigarelli, 18; and Bryan Mort, 19. Daniel Louis Gordon, 20, was wounded.