Grose faced attempted murder, grand larceny over $10,000, as well as two counts of murder.
"My son said he heard sirens and this sort of thing so we knew something was going on," neighbor Karen Griffin said. "We were just shocked."
Friday night, just after 6 p.m., investigators swarmed the area near Kingswood Drive, Mt Gallant Road, and Woodside Drive. They found two bodies in two separate locations, and an injured man who is now in the hospital.
"And the suspect we have in custody was in both those locations," Trent Faris, with the York County Sheriff's Office, said.
Investigators arrested 34-year-old Grose. Neighbors told Eyewitness News that he was no stranger to the River Pines neighborhood.
"I've seen him walking his dog in the neighborhood before," Tanya Hurd said.
Hurd described him as quiet. What many neighbors didn't know was that Grose had a criminal past.
He's been arrested multiple times for DUI and pleaded guilty to a drug charge in 2004. As for what led up to the alleged murders--investigators say they hope the surviving victim will be able to help answer that when he's well enough to talk.
"It's very complicated," Faris said. "It's a lot of puzzle pieces spread out over a large area, and we're trying to put them together again."
But neighbors want them to solve that puzzle as quickly as possible.
"It really scares you," Griffin said.
One of the victims was 53-year-old Sandra Thomas.
Investigators say they were both struck and killed by a vehicle.