A 22-year-old is facing charges for allegedly killing his grandparents in Florida — initially shooting his grandmother inside their residence, and then fatally shooting his grandfather as he sought help from a neighbor, an altercation during which the neighbor’s granddaughter was also shot, police report.

According to the Brevard County Sheriff’s Office, Jeremyah Campbell is accused of murdering his grandparents, George and Mary White, on Wednesday evening around 8 p.m. Authorities say Campbell began by shooting his grandmother multiple times with a handgun inside their West Melbourne home, then targeted his grandfather and the neighbor afterward.

“Just after 8 p.m., one of the neighbors in this neighborhood was approached by the neighbor from across the street — an elderly gentleman who was saying that his wife had been shot and was asking for help,” said Sheriff Wayne Ivey at a press conference on Wednesday night. “As he’s asking for help, from the neighbor’s [house] another round of shots is fired,” Ivey said.

Campbell’s neighbor, Terry French, had a 25-year-old granddaughter who was struck by the gunfire and suffered non-life-threatening injuries, according to police. She is expected to recover.

French spoke to local affiliate NBC affiliate WESH about what allegedly unfolded and how George White, 83, was frantically trying to get his help before being shot. His wife, 81, had already been shot by Campbell at least once.

“George was standing here inside the door, and we had it locked so nobody could get in,” French said. “Somebody over in this area, I think, had a 9-millimeter, and he put these holes in the door,” he alleged, noting how George was shot inside French’s home. “He went in the bathroom … shut the door, and that was it.”

Neighbors in the area described the situation as terrifying in interviews with WESH, with nearly half a dozen gunshots ringing out at one point.

“Five gunshots, a pause, then the last one,” said resident Shea Stewart. “Then, I heard the scream of a woman.”

Campbell is charged with two counts of second-degree murder, one count of attempted second-degree murder, and shooting into an occupied residence.  He was booked into the Brevard County Jail and awaiting his first court appearance Friday.

“George was probably — and Mary — to me, and I’ve been knowing him for 30 years … one of the best neighbors I ever had,” French told WESH. “He’d do anything for you.”

Ivey said Wednesday that police had not yet uncovered a motive, but officers were investigating.