RED LAKE, Minn. — The boy accused of killing nine people in a shooting spree first shot his grandfather and his companion, then donned the man's police-issue gunbelt and bulletproof vest before heading to the high school, where he shot students and teachers at random, authorities said today.

FBI agent Michael Tabman said Jeff Weise appeared to be acting alone in Monday's rampage and the motive was unknown. When it was over, 10 people, including five students and Weise himself, were dead.

It was the worst U.S. school shooting since Columbine.

At a news conference today, Tabman said he couldn't confirm whether Weise was the same person who made posts to a neo-Nazi site, including one in which the writer billed himself as the "Angel of Death."

Aside from the teen's grandfather, Daryl Lusier, and Lusier's companion, Michelle Sigana, Weise's targets appeared random, Weise said. An unarmed security guard and a teacher also were killed.

Initial reports had as many as 15 people injured in the shooting, but authorities today lowered that to seven. Five remained in the hospital, including two students with critical injuries from gunshot wounds to the head or face.

Some of the victims were shot at close range, medical officials said.

Reggie Graves, a student at Red Lake High School, said he was watching a movie about Shakespeare in class Monday when he heard the gunman blast his way past the metal detector at the school's entrance, where an unarmed guard was killed.

Then, in a nearby classroom, he heard the gunman say something to his friend Ryan. "He asked Ryan if he believed in God," Graves said. "And then he shot him." The boy survived.

The death toll at the Red Lake Indian Reservation in far northern Minnesota made it the nation's worst school shooting since the rampage at Columbine High School in Littleton, Colo., in April 1999 that ended with the deaths of 12 students, a teacher and the two teen gunmen.

"Right now we are in utter disbelief and shock," said Floyd Jourdain Jr., chairman of the Red Lake Band of Chippewa.

At least three of the victims were shot in the head at close range, said officials at North Country Regional Hospital in nearby Bemidji. One of those victims died and the other two were transferred to the Fargo hospital.

"I think there was an intent to kill," Tim Hall, the hospital's emergency nursing director, said at a morning news conference. Three victims remained at North Country Regional, none in critical condition.

Police said the gunman killed himself after exchanging fire with officers. Red Lake Fire Director Roman Stately said the gunman had two handguns and a shotgun.

"We ask Minnesotans to help comfort the families and friends of the victims who are suffering unimaginable pain by extending prayers and expressions of support," Gov. Tim Pawlenty said.

Weise, whom authorities described variously as 16 or 17, who had been placed in the school's Homebound program for some violation of policy, said school board member Kathryn Beaulieu. Students in that program stay at home and are tutored by a traveling teacher. Beaulieu said she didn't know what Weise's violation was, and wouldn't be allowed to reveal it if she did.

There was no immediate indication of Weise's motive. But several students said he held anti-social beliefs, and he may have posted messages on a neo-Nazi Web site expressing admiration for Adolf Hitler.

A writer who identified himself as Jeff Weise of the Red Lake Reservation posted the messages under the nickname "Todesengel" — German for "angel of death." An April 2004 posting by him referred to being accused of "a threat on the school I attend," though the writer later said he was cleared.

Tabman said it hadn't been determined if the writer was actually Weise.

Relatives told the St. Paul Pioneer Press that Weise was a loner who usually wore black and was teased by others. Relatives told the newspaper his father committed suicide four years ago, and that his mother was living in a Minneapolis nursing home because she suffered brain injuries in a car accident.

During the rampage, teachers herded students from one room to another, trying to move away from the sound of the shooting, said Graves, 14. He said some students crouched under desks.

Some pleaded with the gunman to stop. "You could hear a girl saying, 'No, Jeff, quit, quit. Leave me alone. What are you doing?"' Sondra Hegstrom told The Pioneer of Bemidji.

The reservation, about 240 miles north of the Twin Cities, is home to the Red Lake Chippewa Tribe, one of the poorest in the state. According to the 2000 census, 5,162 people lived on the reservation.

It was the second fatal school shooting in Minnesota in 18 months. Two students were killed at Rocori High School in Cold Spring in September 2003. Student John Jason McLaughlin, who was 15 at the time, awaits trial in the case.