ROCHESTER, MINN., FEB. 19 -- A teen-ager was charged today with the ax slayings of his parents, sister and a brother as authorities and friends puzzled over the sudden change in the studious, church-going boy.

David Brom, 16, who had shaved the sides of his head and fashioned his hair into a spiked style the day of the slayings, was arrested after an all-night search.

"There's a lot of tears here," said Mike Leahy, principal at Lourdes High School, where Brom was a sophomore. "There is surprise, shock and disbelief. . . . It may subside for a short while, but it will return."

Brom appeared calm during a 15-minute arraignment in which he was charged with four counts of first-degree murder and eight counts of second-degree murder. The charges allege different degrees of premeditation or intent. He did not enter a plea.

County Attorney Raymond Schmitz said the youth was ordered to undergo psychiatric examination and is being held at the Olmsted County jail.

According to the complaint, "One person indicated that on Feb. 17, David Brom said he was going to kill his parents that night, and another person indicated that she had a telephone conversation with David Brom on Feb. 18 during which he told her he had killed his parents."

"No one knew except the friends he told, and they didn't tell anyone," said Charles Von Wald, Olmsted County sheriff. A rumor about the killings finally reached teachers at Brom's school, and they notified authorities.

Bernard Brom, 41, his wife, Paulette, about 40, and children Diane, 14, and Rick, 9, were found dead in their nightclothes Thursday evening at their home in suburban Cascade Township, Von Wald said.

The four were believed to have been slain early Thursday morning, he said. A bloody, 28-inch ax was found in the basement.

Another 16-year-old who spoke with Brom hours before the bodies were found told authorities there had been a dispute between the boy and his father.

"He indicated he was having some trouble with his parents," Von Wald said. "One student said he was having trouble with his dad because of a tape he had bought, and he didn't want him listening to it."

Von Wald and police officials declined to say what the tape contained or whether it had been seized by authorities.

Classmates wept at a Mass at the Roman Catholic school, and neighbors said they had no reason to believe the family was anything but close-knit and loving. About 20 students attended the hearing and tried to hand the boy notes of support.

"There's no indication there was any difficulty in the family," said the Rev. Syl Brown of the Pax Christi Roman Catholic Church. "It's an exemplary family . . . very active in every aspect of the parish. It's a mystery to me."

Brom attended church every week, he said, and babysat for the neighbors.

Each victim had been hit in the head at least once, the sheriff said. Bernard and Rick Brom's bodies were found in their upstairs bedrooms, and Paulette and Diane Brom's bodies in an upstairs hallway, the sheriff said.

"We believe the father and son were probably surprised and didn't have a chance to defend themselves," Von Wald said. "We believe the mother and daughter were going to investigate and were confronted."

Police were called to the house about 5:30 p.m. on a tip from an unidentified school official. After a nightlong search, Brom was apprehended at a post office.

The boy had bought a wig and makeup, possibly for use as a disguise, Von Wald said.