"It's senseless and just very tragic," said Police Capt. James Clark.
The two suspects, Von Combs, 14, and India Spellman, 17, live close to Greaves' neighborhood but did not know him, police said Monday. They were arrested Friday and charged with murder, robbery, and other crimes.
"It made me feel pretty sick," said Beth Morris, Greaves' second cousin, when she learned about the accused teens.
"There's nobody watching over them," added Morris, 48, of Abington. "They're punks. It's sad."
Spellman had no criminal record, said Clark. Combs has only a minor offense in his past.
Acquaintances recalled Greaves, a World War II veteran, as a private but friendly gentleman who lived alone, had few visitors, and was often seen taking special care of the greenery in front of his well-kept house. He never married and did not have children.
"He didn't bother a soul," said neighbor Kathy Mathis. "He was really a nice man."
Mathis was nearby when Greaves was killed around 3 p.m. Greaves had just finished cutting his grass when Spellman and Combs approached him, police said. The teenagers brandished a gun and demanded money, then shot Greaves in the chest.
"From what we can tell, he didn't move as quickly as they may have wanted him to," Clark said. "They maybe took that as some type of resisting, or disrespect."
Mathis heard gunfire and, seconds later, saw the teenagers running from the scene.
"They didn't have to kill him," Mathis said. "He's 87 - they could punch him, knock him down. It's just unbelievable that something like this could happen."
Willie Bullock, who lives across the street from Greaves' house, said he felt relieved when he heard the police arrested the alleged shooters.
"We're all glad to see people like that off the streets," he said.
Greaves served as a Navy Seabee in Guam during World Ward II, relatives said. He later worked at the Budd Co. plant in Nicetown, where he retired as a machinist. He spent weekends during the summer at the Jersey Shore and winters in the Poconos at a house owned by relatives.
He enjoyed fishing. He was also a fitness enthusiast and, for many years, a body builder, relatives said. The afternoon he died, he had worked out at a gym in Elkins Park.
The teens have been charged as adults. Any person 13 and older who is charged with murder is automatically charged as an adult, but a judge can send any minor into the juvenile system, where the maximum age for incarceration is 21.
Contact staff writer Allison Steele at 215-854-2641 or firstname.lastname@example.org.