Michael Guzzo shot dead 4 neighbors and dogs because of animals' barking Guzzo's ex-wife who was married to him for 20 years says he had mental health issues that he refused treatment for By Michael Zennie and Ashley Collman 'He snapped': Michael Guzzo (pictured above) went on a shooting spree before killing himself Saturday, and detectives believe barking dogs sparked the rampage The ex-wife of the man who murdered his four neighbors and killed their two dogs Saturday because the canines wouldn't stop barking loudly, says there were warning signs he would snap. Michael Guzzo, the 56-year-old gunman, became enraged over the noise from the pets at a neighboring townhouse in a Phoenix apartment complex, detectives say. They believe the pharmacist used a pump-action shotgun to shoot dead Bruce Moore, 66; his daughter, Renee Moore, 36; her husband Michael Moore, 42 (who took his wife's last name); and their son, Shannon Moore, 17. Guzzo then fired several rounds into the door of another neighbor.He returned home and killed himself. The woman who was married to Guzzo for 20 years described him as a 'troubled soul' who struggled with depression, paranoia and self-esteem issues. And she would know - she's a behavioral health nurse. The former Mrs Guzzo says she wasn't surprised when she heard the news. I watched the news at 5 and I went "Oh my God." And I knew. I knew Mike was the shooter, I knew he was dead,' she told AZCentral. His ex-wife says she decided to talk to the media in order to give the Moore family a better idea of what happened the day of the shooting, but wanted to remain unnamed. When he moved into the apartment a year and a half ago, she says he was angry and depressed. She adds that he was so angry about the neighborhood's barking dogs that he left several notes on doors around the apartment complex. Stained: Patrick Riley, brother of shooting victim Michael Moore, surveys the damage at the scene of Saturday's shooting rampage His attitude was creeping into his professional life as well, and Guzzo was having a hard time keeping jobs at pharmacies. She also believes he was suicidal and probably woke up that morning deciding to die. The barking dogs gave him an excuxse. 'It just culminated,' she told ABC 15. It was the perfect storm. She says the Moore family 'were in the wrong place at the wrong time' and argued with the wrong person. She believes her ex-husband simply 'snapped'. Still, she maintains that her Guzzo was a good person and she never felt in danger around him. She says that in the years leading up to their divorce she tried to get him treatment but he refused and started to isloate from the entire family. Remembered: A memorial has been set up outside the Moore house where three generations of the family were slaughtered when Guzzo 'snapped', allegedly due to their barking dogs Mike had worth. He never felt he had worth - he had worth,' she told FOX 10. He was a good person that did a very bad thing. Struggling: Guzzo's ex-wife said his mental health issues were making it hard for him to keep jobs as a pharmacist But she says, he shouldn't have owned a shot gun. 'For him to have a weapon like that, it's just a recipe for diaster.' Several of Guzzo's neighbors say he was a quiet man and that they were shocked by his sudden violent rampage.