Authorities in Pennsylvania have arrested three men suspected of being involved in a shooting that left a man and his 7-year-old son dead this week.

According to WPXI, 29-year-old Walter Stewart Jr. and his son, Jo Lawrence Stewart, were killed during what appeared to be an exchange of bullets inside a Swissvale home around 4:30 p.m. Tuesday.

The father was pronounced dead at the scene and the child died a short time later at a Pittsburgh hospital, according to the Post-Gazette.

According to police, 23-year-old Donavan Wilson, 26-year-old Brandon Barnett and 30-year-old Jacqua Barnett were each arrested Wednesday and will face homicide and conspiracy charges.

Brandon Barnett was also reportedly shot multiple times during the incident and was transported to an area hospital by the other two suspects. Initial reports listed him in critical condition and he is set to be jailed immediately following his discharge from the hospital.

Police are still trying to confirm a motive in the attack, according to Allegheny County Police Lt. Andrew Schurman.

“It might be drug related and there might’ve been some type of robbery attempt,” he said.

One witness described to police hearing Wilson say he “did not sell outside the house,” which was followed by the sound of six or seven gunshots.

The mayor of nearby Braddock said he knew the victims and had a son near Jo Lawrence’s age.

“It stuns and appalls me and breaks my heart and it should everybody’s,” John Fetterman said.

[Featured image: Brandon Barnett, Donavan Wilson, Jacqua Barnett/Allegheny County Police]