Two towns united in sorrow after a massacre that took place at the body of water that has always divided them.

Mourners in Niagara, Wis., and Kingsford scrawled "rest in peace" in crayon on signs in car windows and hung posters in store windows urging residents to "pray for the families."

Two days earlier, an armed Scott J. Johnson allegedly jumped from bushes and opened fire on a group of at least five young swimmers who were relaxing by a popular bridge over the Menominee River. Three teens were killed, and a 20-year-old was injured.

Johnson disappeared for nearly 16 hours after the shooting before emerging from a wooded area, throwing down his rifle and surrendering to police.

The 38-year-old was expected to appear in court Monday or Tuesday, said Jerry Sauve, Marinette County chief sheriff's deputy. He said it wasn't yet clear whether charges would be filed before that court appearance.

Investigators have not determined a motive. Authorities say there was no communication between the gunman and his victims.

Johnson is also accused of sexually assaulting a 24-year-old woman at the same site a day before the shooting. Authorities said it wasn't clear whether the assault on Wednesday was related to the shooting, and Johnson has not been charged with sexual assault.

Sauve didn't know whether Johnson had a lawyer, and a phone message left with the district attorney was not returned Saturday.

Hundreds gathered in a church Friday to seek solace and remember the victims: Tiffany Pohlson, 17; Anthony Spigarelli, 18; and Bryan Mort, 19. A fourth victim, 20-year-old Daniel Louis Gordon, was wounded. All were from Michigan.

After the church service, dozens of teens stood in the parking lot in embraces, their silence punctuated by occasional sobs. Half an hour later, some began to smile and laugh as they exchanged memories of the victims.

Most were best acquainted with Spigarelli, who had just graduated from Kingsford High School and had talked about becoming an engineer.

"Even my mom is in love with him," said Beth Murray, 15, drawing smiles from about 10 other girls who nodded and dabbed their eyes. "There's not another person in town like him."

The three teens who were killed had been spending time at the "river bridge," a remote hangout well-known to generations of locals. A railroad bridge passes over the river between the two states, and kids would often gather in the summer to swim.

"I used to go up there 30 years ago, and then my boys went up there when they were teens," recalled Judy Schultz, 45, a supervisor at a Kingsford motel. "Now you wonder if the memories are so bad that anyone will go out there anymore."