No one seems to know why a man shot his son and a dog Monday afternoon before turning the gun on himself while he had Orem emergency dispatchers on the telephone.

Rex W. Black, 47, dialed 911 from his apartment about 4:30 p.m. and told a dispatcher that he had just shot his son, said Orem Police Lt. Bob Conner. The dispatcher then heard a single gunshot.Police arrived a few minutes later to find Black dead in the living room at 1274 N. State St., Apt. 4. His 22-year-old son, Tobias "Toby" Black, was dead in the kitchen. Both had suffered gunshot wounds to the head, Conner said.

A Chihuahua also died from a gunshot wound. An iguana police discovered in the apartment was not harmed.

Police found a Russian-made Makarov 9mm handgun near Rex Black's body. Conner said he didn't know who owned the gun.

Amy Nau, a close friend of Toby Black who gave him the dog named Loki, said the father and son were inseparable and had lived together the past eight years.

"They were very, very close," she said.

Nau can't imagine that anger or an argument precipitated the killing.

"I think if anything it was done out of love," she said. "Maybe Rex didn't want to die alone. That's one part that's hard to understand. I don't think it's fair."

Police have not come up with a reason for the shooting, either.

"It's a puzzle. The two people who know why it occurred are not here anymore," Conner said.

Tenants in the seven-unit motel-turned-apartments didn't know much about the Blacks. Next-door neighbor Jeff Ruble said they moved to the apartment less than a year ago. The father and son kept to themselves, he said.

Rex Black was a "nice guy," Ruble said, adding he didn't detect anything that might be troubling his neighbor. Ruble, who has lived at the apartments for four years, said he last saw Rex Black a day or two ago when they waved to each other in the parking lot.

"I was totally shocked to find out about this," said Charles Waggoner, Rex Black's boss at Burrelle Press Clipping Service. "We are saddened about this tragedy."

Toby Black took humanities and general studies courses at Utah Valley State College during the 1994-95 school year. Nau, who worked with Toby Black at Sears Teleservice Center, said he planned to go back to school and was most recently building log furniture for a local company. She described Toby Black as a fun person to be around.

"He was really funny and sarcastic."

The Blacks moved to Orem from Spanish Fork last July. Toby Black attended Spanish Fork High School, and those who knew him called him a "nice kid."

"He wasn't one to go off and do the really wild things. He just looked it," said Karen K. Payne, a former neighbor in Spanish Fork. "I can't believe any of this was Toby's idea."