PHOENIX -- For months, Michael Guzzo complained to neighbors about incessant dog barking, even putting up fliers on doors throughout his Phoenix townhome complex advising people of pet ordinances and fines.

This weekend, police say, Guzzo went on a rampage, methodically killing four members of a family and their two dogs that lived next door before killing himself with the same shotgun.

While his motive died along with him, neighbors and family members of the victims say he was becoming increasingly unhinged over dog noise.

Neighbors in the complex of two-story townhomes where a central courtyard looks like a tree-laden park said Guzzo made no secret that the barking dogs were irritating him.

He often left printouts of the city’s dog barking ordinance on doors throughout the community, said Joni Flood, 21, who lives a few doors down from the victims.

“He hated them. But everyone here has dogs,” Flood said.

On Saturday, police say, Guzzo shot and killed neighbor Bruce Moore, 66; his daughter, Renee Moore, 36; her husband, Michael Moore, 42, who used his wife’s last name; and Renee’s son, Shannon Moore, 17, along with the family’s two dogs.

Guzzo, 56, then walked across the courtyard and tried to kill more neighbors who had dogs, neighbors whom he had confronted in the past.

Libni Deleon, 26, said that just a few months ago, he returned home from work to find Guzzo standing by his back gate where his two dogs were on the patio barking. “He said, ‘Your dogs are barking. I’m here to live in peace,”’ Deleon recalled.

On Saturday, moments after killing four people and two dogs, Guzzo went to Deleon’s home and began kicking on the front door.

Libni Deleon’s wife, Vanessa, who had just gotten out of the shower, grabbed their two children and ran upstairs to hide in the bathtub.

Libni Deleon went toward the door as Guzzo blasted two holes through it, sending about 20 shotgun pellets into the walls at the back of their home.

Deleon ran upstairs to get his own gun, opened the window and began to yell at Guzzo, who opened fire again before walking back to his own home to kill himself.

“I feel pretty darn lucky,” Deleon said.

While Guzzo’s motive died along with him, neighbors and family members of the victims say he was becoming increasingly unhinged over dog noise.

“He hated them. But everyone here has dogs,” said Joni Flood, 27, who lives a few doors down from the victims.

Family members, meanwhile, struggled to come to grips with their loss, dumbfounded by the sheer senselessness of the killings.

Standing amid pools of drying blood on the home’s back patio where the two men were apparently shot first, Michael Moore’s brother called the killings “angering beyond belief.”

“It just angers me looking at all this because I just feel for my brother,” said Patrick Riley, 41. “The helplessness.”

The patio wall was chipped with pockmarks from the shotgun’s blast. Police haven’t given specific details of the attack, but Riley said he thinks Guzzo shot his brother over a 6-foot cinderblock fence while he worked on an engine.

“He had no idea what was coming,” Riley said. Bruce Moore was killed a few feet away near the patio door to the home.

Riley said police told him Guzzo killed the two men first, then walked through the family’s unlocked front door and shot Renee, her son, Shannon, and the dogs.

The killer was no stranger to the family, even though they had little contact with him, Alderman said.

Renee Moore had told her repeatedly “the man was crazy. He can’t stand the dogs.”

Alderman sobbed Monday as she stood outside the home while other family members gathered on the porch where the two men, including her son, were shot.

“I don’t want to see the blood,” she said with a heavy sigh.

Phoenix Sgt. Steve Martos said authorities can only speculate on a motive for the killings.

“If he had left a note, maybe,” Martos said, “but nothing like that occurred in this case.”