Philadelphia police were trying to piece together two incidents of family violence in North Philadelphia over the weekend that left a grandfather and step-uncle dead in one attack, and a 13-year-old boy clinging to life in the other.

On Monday, police said Czar McMichael, 22, had been struggling with mental illness and that may have led him to fatally shoot his grandfather, Benjamin McMichael, 67, and step-uncle, Anthony Ham, 45.

McMichael shot his grandfather inside their home on the 4600 block of North Broad Street on Thursday, police said, after the older man confronted him over the uncleanliness of his bedroom.

Two days later, at 4:40 p.m. Saturday, Ham, accompanied by an aunt of Czar McMichael’s, went to the house to check on the grandfather after not seeing him for two days. Ham entered the house through a window, and once inside, opened the door for the aunt, police said.

While checking the home, Ham confronted Czar McMichael on a staircase leading to the third floor, said Homicide Capt. Jason Smith. After an argument, McMichael attempted to shoot Ham with a handgun that jammed, then retrieved a second gun ― the same .22-caliber handgun he used to kill his grandfather ― and shot Ham multiple times then fled the home on foot, Smith said.

The aunt called 911 and officers took McMichael into custody a short distance away in the 4500 block of North 13th Street, police said.

“From what I understand, there may have been some mental health issues that were going on with Czar McMichael,” Smith said, noting that it is unusual for someone to remain in a home with the body of someone they have killed.

McMichael had no criminal record before his Saturday arrest, Smith said. In 2019, The Inquirer featured McMichael in an article about a workforce development program. At the time, McMichael, a 2017 Martin Luther King Jr. High School graduate, said he was working for his grandfather’s construction company and was motivated by his new job prospects after graduating from the program.

McMichael was denied bail and remains in custody.

On Monday, no one answered the door at the McMichaels’ home. A next-door neighbor declined to comment.

In another spate of gun violence, police said a 13-year-old boy was accidentally shot by his older brother in the family’s home on the 2200 block of North Woodstock Street.

Police said Ellijah Simmons, 20, handed his younger brother the loaded gun, and it accidentally discharged. Simmons and his girlfriend, Caresa McFarland, 32, then hid the firearm in a closet, according to police.

After telling several versions of what happened, Simmons admitted that he accidentally shot his brother, a police source familiar with the investigation said Monday.

“It was an accident. It wasn’t a struggle or argument. He just got careless with his firearm,” said the source, who spoke on the condition of anonymity because he is not authorized to speak about the case.

The victim, he said, remains in extremely critical condition.

Simmons was charged with aggravated assault, endangering the welfare of a child, and related crimes. McFarland, 32, was charged with recklessly endangering another person. Simmons, who’s barred from possessing a gun because of a prior conviction in Family Court, according to court records, is being held on $1 million bail. McFarland was released on $100,000 unsecured bail.