A 13-year-old Pennsylvania boy charged with fatally shooting his grandparents in their home was upset because they called his mother a "whore" and were "speaking poorly about her," according to state police and court documents.

Zachary James Proper, of Oil City, was arraigned Tuesday morning as an adult before District Judge Michael Snyder in Franklin, Pa., on two counts of criminal homicide. He was remanded to Venango County Jail without bond, Pennsylvania State Police said.

Troopers found the bodies of Dorothy Fross, 67, and George Fross, 69, on Monday night in their home in Sandycreek Township in Venango County. They went there after the Frosses’ son – the boy’s father – called police to ask them to check on the couple’s welfare.

Proper's parents were concerned that their son had gotten drunk and high on Sunday night and had stolen a car belonging to his grandparents, police said in a criminal complaint, The Associated Press reported.

Proper lived about 10 miles away in Oil City with his parents but often spent time at his grandparents’ home, investigators said.

Police believe the Frosses were shot in their home late Sunday afternoon.

Watch US News crime videos on NBCNews.com

According to the police affidavit, the boy admitted to the killings, the Pittsburgh Post-Gazette reported. The affidavit outlined this sequence of events, according to the Post-Gazette and the AP:

Proper used bolt cutters to break into a gun safe at his grandparents’ home and took a handgun. He put on headphones, sneaked up behind his grandmother and fatally shot her. He then called his grandfather and told him that he would meet him at the front door to help him carry in groceries. When the grandfather came home, Zachary took a pizza from his hands and then shot him repeatedly until the gun jammed.

Asked to explain the shootings, the boy told police “that he was mad at his grandparents because they had called his mother a whore and were speaking poorly about her.” Police did not elaborate on the remarks.

The boy told police he then drove his grandparents' car to Oil City, dumped the gun in a storm drain and spent the night partying at a cousin's house, the Gazette and the AP reported, citing the affidavit.

More content from NBCNews.com:

• Jerry Sandusky gets 30 to 60 years for child sex abuse
• Cook County, Ill., considers 'violence tax' on guns, ammo
• 1 in 5 Americans are not religiously affiliated, survey finds
• Deadly crossing: Death toll rises among those desperate for American Dream
• Military suicides: Defense officials spending $10 million to learn if fish oil can help
• Video: Mexican authorities arrest suspect in tourist murder

Follow US news from NBCNews.com on Twitter and Facebook

Eduardo Munoz / Reuters

Matthew Badger, left, and Madonna Badger cry during the arrival of their daughters' caskets during their funeral service Jan. 5 in New York.

The father of the three girls killed in a Christmas morning house fire has sued the city of Stamford, Conn., his ex-wife's contractor boyfriend and several others who did work on the home, saying they all had roles into making it into a "firetrap."

Matthew Badger's lawsuit, filed Wednesday in Superior Court, alleges that contractor Michael Borcina failed to install a smoke detection system while doing renovations on the $1.7 million Victorian house in Stamford. Borcina escaped the blaze along with the girls' mother.

The fire killed 7-year-old twins Grace and Sarah Badger, 9-year-old Lily Badger, and their grandparents Lomer and Pauline Johnson.

The lawsuit alleges that Borcina was to oversee installation of a hard-wired smoke detection system after beginning renovations at the three-story waterfront home but failed to complete the project as scheduled in April 2011 and left the ground floor without heating.

"The girls died before they could escape the home, which had become a firetrap as a result of months of substandard construction leading up to the fire," according to the lawsuit, which was first reported by The Stamford Advocate.

The lawsuit also says city officials knew or should have known that Borcina served as the home's general contractor but didn't have a state home improvement contractor's license.

Stay informed with the latest headlines; sign up for our newsletter

Borcina's criminal attorney, Eugene Riccio, said Thursday that another attorney was being hired to handle the civil case. Stamford's director of legal affairs, Joseph Capalbo, declined to comment.

The home's architect, electrician and general contractor listed on the building permit were included as defendants.

No criminal charges in Christmas fire

Last month, Stamford State's Attorney David Cohen said he found no criminal negligence in investigating the fire, which has been blamed on a bag of fireplace ashes that had been discarded in a mudroom.

The grandparents' estates have notified the city of their intent to sue.

Man died trying to save granddaughter

The girls' mother, Madonna Badger, told NBC's "Today" show last month that the bag of ashes didn't seem dangerous because Borcina ran his hands over them before putting them on top of a plastic bin.

More content from msnbc.com and NBC News:

• Report: Paterno, others hid Sandusky sexual abuse
• Prosecutor releases another round of Zimmerman evidence
• Caught on camera: Shark steals fish off pole
• Guantanamo detainee who served bin Laden returns to Sudan

Follow US News on msnbc.com on Twitter and Facebook

Sarasota County Sheriff's Office | WFLA

The deputy who stopped the procession said the toy car was attached to the SUV with two dog leashes.

Two drunken grandparents were arrested for using their vehicle to pull their 7-year-old granddaughter in a toy car, the Sarasota County Sheriff's Office said.

Belinda and Paul Berloni were arrested on Sunday after a deputy in a marked patrol car saw the SUV pulling a "small plastic hot wheels car" along an access road, authorities said. The vehicle was going about five to 10 miles per hour, the probable cause affidavit said.

The girl was wearing a bathing suit with no protective gear, authorities said. The toy car was attached to the SUV with two dog leashes tied to the trailer hitch, the affidavit said.

Read the original report at NBCMiami.com

Paul Berloni, 49, smelled of alcohol and his eyes were bloodshot and watery, the affidavit said. When asked for his driver's license, he said it had been revoked for 10 years for a DUI. He also told authorities he had two or three drinks, authorities said. He later said it was more but wasn't specific, the affidavit said.

Sarasota County Sheriff's Office | WFLA

Belinda and Paul Berloni

Belinda Berloni, 47, was in the cargo area with the rear hatch open cheering the little girl on, the affidavit said. She was also intoxicated and said she had a few drinks, authorities said.

She "also stated that she understood that it was dangerous to drag a child behind the vehicle but stated they were just having fun and had been doing it all day," the affidavit said.

Belinda Berloni's son, who is the girl's father, arrived and was upset with his mother. He also said that he believed they had a drinking problem that may have affected their decision making, the affidavit said.

Watch the Top Videos on msnbc.com

"The defendant and co-defendant failed to provide adequate supervision for the child and put the child in a situation that could have easily resulted in great bodily harm, permanent disfigurement and even death," the affidavit said.

Sarasota County Sheriff's Office | WFLA

The deputy who stopped the grandparents said the grandmother was in the back of the SUV calling encouragement to the 7-year-old girl.

Paul Berloni refused to take a field sobriety test and was being held on $7,500 bond on Monday, a jail official said. He faces charges that include a fourth DUI offense, driving with a suspended license and cruelty toward a child. Belinda Berloni was released from jail Monday on supervised release and faces a child cruelty charge.

It wasn't immediately known if they had attorneys.

More content from msnbc.com and NBC News:

• Occupy activists fear becoming Democrats' 'pet'
• Bin Laden's lair: Hatching plots with no one to execute them
• Mom, son killed in separate car accidents hours apart
• Anarchists nabbed in alleged plot to bomb Ohio bridge
• EPA official resigns over 'crucify' philosophy

Follow US News on msnbc.com on Twitter and Facebook