A Wisconsin judge set a $3 million cash bail for the Michigan man charged with shooting and killing three teens at a river on the state border.

Marinette County District Attorney Brent DeBord had asked for $5 million bail, calling Scott J. Johnson an “extreme flight risk” because he spent time in the military and has traveled extensively. Johnson’s public defender had asked for $1 million bail.

Johnson, 38, of Kingsford, Mich., was charged with three counts of first-degree intentional homicide. According to a criminal complaint, he went to the Menominee River on July 31 and opened fire on a group of swimmers, killing three and injuring one.

One charge each of attempted first-degree intentional homicide and sexual assault could be added, DeBord said Thursday. Johnson told police he sexually assaulted a woman at the river the day before the shooting, the complaint said.

In addition, a Michigan prosecutor said Thursday he has asked federal authorities to charge Johnson in the death of one victim whose body was found on the Michigan riverbank. Johnson was charged in Wisconsin because he fired the shots from here.

But federal prosecutors could seek the death penalty, which is not possible in Wisconsin or Michigan, said Chris Ninomiya, a prosecuting attorney for Dickinson County in Michigan.

DeBord said he has not made a formal request for federal assistance, but the crime occurred on railroad property, which might give the federal government jurisdiction.

“We’re continuing to have discussions with this to see what federal jurisdiction might exist,” said Kaye Hooker, spokeswoman for the Western Michigan U.S. Attorney’s office.

Dean Puschnig, law enforcement coordinator for the Eastern Wisconsin U.S. Attorney’s office, said officials there were also looking into jurisdictional issues and also have not made a decision about getting involved.

Johnson and his public defender, Len Kachinsky, appeared in court by videoconference. Kachinsky later said he was not surprised by the bail amount or the possibility of further charges.

Marinette County Circuit Judge Tim Duket set a preliminary hearing for Aug. 20.