An Isanti, Minn., teenager gave his mother five $100 bills for Christmas, asking her not to tell his grandparents about the gift, and he gave his father a car, according to authorities.

The sudden burst of generosity and need for secrecy were because the teen had just made off with as much as $250,000 in $100 bills that his grandfather kept in a lockbox in his home in Amery, Wis., according to a criminal complaint filed this week against Andrew P. Selvig, 18.

The teen and a friend, Samuel Durkot, 19, of Cambridge, Minn., had stayed overnight Christmas Eve in the home of Dana and Lou Berning, police say, and managed to get the lockbox out of the house Christmas morning.

The car that Selvig gave his father was one of six that the pair bought -- at prices of $1,200 to $14,000 each -- from private sellers on Craigslist, said Sgt. Ray Joy of the Polk County Sheriff's Office. They also bought a load of electronic gear, police said, and authorities have seized it all.

Selvig and Durkot were each charged this week with felony theft in Polk County Circuit Court in Wisconsin. Bail was set at $10,000 Friday for Selvig, who was arrested at his father's home in Lake City, Minn.

Durkot was driving one of the vehicles when police stopped him Tuesday in Elizabethtown, Ky., with a runaway teenage girl from Anoka. He awaits extradition to Polk County.

Inside the 2001 Ford Focus he was given, Selvig's father found a lockbox with a drilled lock matching the one stolen from the grandparents' home. Police have recovered about $140,000 of the money.

Reached at her Isanti home Friday, Selvig's mother, Renee Havelka, 37, had no comment. Her parents were the victims of the theft.

The two teens also gave generous cash gifts to friends, and three or four have reported receiving money, although some of it was spent, said Joy. He said friends reported a total of more than $2,000 in cash gifts.

The charges say Selvig lived with his grandparents for nine months and may have learned about the lockbox where the couple kept a stash of $100 bills. Lou Berning, 56, told police that they had collected big bills from their restaurant, Chisago House in Taylors Falls. Whenever they were paid with a $100 bill, Lou Berning took it as her pay, she said. They kept a tally of the bills and said they had between 2,300 and 2,500 in $100 bills in their lockbox, hidden behind the basement steps.

The two teens slept in the basement on Christmas Eve and drove home the next day to Renee Havelka's Isanti home, ahead of the Bernings. Lou Berning told police her grandson told her before Christmas that he was broke, so she gave him $20 to drive to Amery for the holiday. When Havelka told her father about the $500 gift, he said Selvig had stolen money from his restaurant, and he wondered where his grandson, who had no job, got the Christmas cash.

Selvig initially denied the theft, but later implicated himself, police said.

The Bernings didn't return calls Friday.

The Amery couple "was pretty brokenhearted," Sgt. Ray Joy said. He said the grandfather "felt a violation of trust. On the other hand, he also lost a quarter-million dollars."

Jim Adams • 612-673-7658