Barbara J. Olson was bludgeoned with a hammer and hatchet before being robbed of her spare change, police said. Her great-grandson and his friend are accused of carrying out the crime then going out for pizza.

SHEBOYGAN COUNTY SHERIFFS DEPT.

Two 13-year-old Wisconsin boys have been charged with first degree murder for the brutal slaying of one boy's great-grandmother, whom they allegedly bludgeoned with a hammer and hatchet before robbing her spare change and going out for pizza.

Both boys, Antonio D. Barbeau and Nathan J. Paape, were charged Friday as adults in the death of Barbeau’s great-grandmother, 78-year-old Barbara J. Olson, prosecutors said.

In a crime that was both gruesome and callous, the boys are accused of going to Olson’s Sheboygan, Wis., home on Sept. 17 “to get some money,” the Milwaukee Journal Sentinel reported.

Barbeau allegedly told his friend they should kill the elderly woman and they armed themselves with a hammer and hatchet.

The boys got a ride to Olson’s home from Paape’s mother and they “hid their weapons in their clothing,” police said.

They entered the house through an unlocked door and when Olson said she was going to call Barbeau’s mother, the teen allegedly struck her in the head with the blunt end of the hatchet.

WISN

She fell to the ground but police say Barbeau continued to strike her with the back of the hatchet “as she tried to cover her head, groaning and telling them to stop.”

Paape then struck her twice with the hammer, police said.

Her great-grandson turned the hatchet around and hit her in the head with the blade, police said.

The teens then ransacked the house, taking a purse, loose quarters and jewelry, according to prosecutors.

They also allegedly tried to dispose the victim’s body, dragging her to the garage, but then abandoning the plan.

Instead, prosecutors say the teens stole Olson’s car and eventually left it at a Sheboygan bowling alley. From there, they walked to the pizza restaurant.

Olson's body was found on Wednesday.

"I don't understand how anyone much less 13-year-olds can be so unfeeling about someone to after they kill her, go to have a pizza," Sheboygan County District Attorney Joe DeCecco said.

Both Barbeau and Pappe have admitted to police they killed Olson, the Sentinel said.

They are being held on $1 million cash bond.

Barbeau's defense attorney told a local TV station he will try to have the case moved to juvenile court.