MARINETTE, Wis. -- At least two of the three teens killed in a shooting last week in Wisconsin died from single gunshot wounds to the head.

Marinette County Coroner George Smith said Tiffany Pohlson, 17, of Vulcan, Mich., and Anthony Spigarelli, 18, of Iron Mountain, Mich., were each shot once Thursday and died instantly.

The autopsy for the third victim, Bryan Mort, 19, of Iron Mountain, is being done in Michigan because his body was found on that side of a bridge connecting the two states.

A hospital pathologist overseeing Mort's autopsy did not immediately return a call Monday.

Scott Johnson, 38, of Kingsford, Mich., was arrested Friday. He remains jailed in Marinette County but hasn't yet been charged.

The Marinette County district attorney is reviewing possible charges against Johnson. The DA said Johnson will not have a court appearance Monday.

Police allege that on Thursday afternoon, Johnson emerged from a bush dressed in camouflage and opened fire on the teens as they relaxed along the Menominee River between the Wisconsin and Michigan borders.