Litchfield Park, AZ – An 11-year old boy fatally shot his grandmother on Saturday evening, then used the same weapon to kill himself, police said.

The tragic incident occurred after 65-year-old Yvonne Woodard repeatedly asked the boy to clean up his room, KSAZ reported.

Woodard and her husband, Doyle Herbert, had full custody of their grandson, who resided with them at their home on West Grove Street, according to the Miami Herald.

Despite repeated requests throughout the day, the child refused to clean his room or to pick up after himself, Herbert told police.

“He was being stubborn about it,” Maricopa County Sheriff’s Office spokesperson Joaquin Enriquez told WPVI on Sunday.

Later in the evening, as Herbert and Woodard were sitting on the couch watching television, their grandson snuck up behind them, and fired a round into the back of Woodard’s head.

The handgun belonged to Herbert, Enriquez said.

Herbert said he initially chased after his grandson, then stopped and went back to try to help his wife.

Seconds later, he heard another gunshot.

Herbert said the boy took several steps, then fell to the ground with a self-inflicted gunshot wound.

After retrieving his weapon, the elderly man contacted 911.

Maricopa County Sheriff’s Office investigators said there were “no previous signs that the grandson might harm someone or himself, and there was no cause for concern prior to this event,” the Miami Herald reported.

Neighbors were shocked to hear about the tragic murder-suicide, KTVK reported.

“We stood outside and we prayed,” resident Danny Dillon told the news outlet. “It’s just hard. You can’t get your mind around it. You just can’t.”

“You have that neighborhood connection but your heart just wishes that you had more and you could’ve done more, you could’ve seen something or said something,” Dillon said.

Neighbor Walter Venerable described the trio as a “nice family.”

“I knew the kid,” Venerable said. “I mean, he would ride his bicycle around, play around the neighborhood.”

According to a letter sent to parents and guardians by the Litchfield Elementary School District on Monday, the boy was a student at Western Sky Middle School.

“We are heartbroken to learn of the tragic death of one of our students and his grandmother,” the letter read. “They were valued members of our Wildcat family…and will be deeply missed. Our hearts are with the Herbert family and their loves ones as they endure this unimaginable pain.”

The school district said they would provide counselors and support to staff and students in the wake of the incident.