Still no answers in Phoenix quadruple homicide

Laurie Merrill and Jackee Coe | The Arizona Repbulic

Show Caption Hide Caption 4 adults, 1 teenager dead in Phoenix shooting Phoenix police say a man killed three adults and a teenage boy before killing himself Saturday, Oct. 26, 2013.

Three adults%2C one teen killed before gunman killed himself

Two dogs also were killed%3B speculation that gunman had %27low tolerance for dogs or noise%27

Gunman lived next door to victims

PHOENIX -- Phoenix police said Sunday that they may never learn exactly why a 56-year-old man fatally shot a family of four who lived next door before killing himself in a townhouse complex in Phoenix.

But neighbors in the family-oriented, 250-unit complex said the shooter often argued with pet owners about barking dogs and left written notes complaining about the noise.

"He didn't want noise," neighbor and dog owner Denise Lopez said. "The dogs were waking him up. He always used to complain."

What is known, according to police, is that Michael Dante Guzzo took his pump-action shotgun and, at about 9 a.m. Saturday, fatally shot his next-door neighbors: Bruce Moore, 66; his daughter, Renee, 36; her husband, Michael, 42, who took his wife's last name; their son, Shannon, 17; and two dogs.

Guzzo then began walking to a unit across the courtyard, where a Chihuahua and pit bull had started barking at the gunfire, the dogs' owner said.

Guzzo banged and kicked the front door, said Libni, who lives at the unit and declined to provide a last name. Libni's girlfriend had just left the shower and was trying to open the door and hold a towel around herself at the same time, he said, but he sent her upstairs to be with the two children.

"That's when he fired through the door," said Libni, who was standing to the side at the time.

Guzzo then began to walk away as Libni raced up to the second floor, retrieved his gun and opened a window, he said.

"A man's got to protect his family," Libni said.

At the sound of the window opening, Guzzo raised the shotgun and fired, shattering the glass, Libni said. He said he had just ducked.

"It's a miracle," he said.

Guzzo then walked across the courtyard to his unit, went inside and fatally shot himself, police said.

On Sunday, neighbors congregated on the grass between units, many with dogs. Others strolled, and several children rode bikes. Some stopped by the Moore home and left items including flowers, candles and a stuffed animal.

Those interviewed said they were shocked by the violence committed by a "quiet" man. The president of the complex's homeowners association said crisis counselors were scheduled to arrive Monday.

When the shootings began, several neighbors said, it sounded like construction.

Barry Hatchett, 49, said he heard a "boom boom boom boom."

"Then I heard four bangs," Hatchett said. "I looked out the window and saw him (Guzzo) walking with a gun. Then he stopped and reloaded."

Hatchett said Guzzo was walking across to Libni's unit. He called 911.

Hatchett's wife, Charise, 42, said that Renee Moore had five dogs, all small breeds. She had just gotten several out of quarantine. They had been quarantined after she and her husband moved to Phoenix from China, she said.

"Everyone who lived here had to know Renee," Charise said. "She was always outside walking her dogs."

Shannon also was a familiar sight. He had a disability, neighbors said, and was often seen running to the school bus and playing with younger children.

Officers who responded to the scene and searched for the gunman discovered the slain Moore family inside their home Saturday, and then Guzzo's body in his townhouse, Phoenix police Sgt. Tommy Thompson said.

Thompson said Guzzo's motive is "one of the troubling questions we have."

"There is some speculation that perhaps it may have been that Mr. Guzzo had a low tolerance for dogs or noise," Thompson said. "This is an incident where we just don't know what sparked this."

There appears to be no history between Guzzo and the Moore family, and it did not appear that police had responded to either residence in the past, Thompson said.

Guzzo apparently lived alone.

Investigators hope the results of the autopsy reports can shed more light on the homicides.