KALAMAZOO, Mich. (NEWSCHANNEL 3) - We're uncovering new details tonight about the man who police say went on a murderous rampage in two West Michigan counties late last month.
Zachary Patten is charged with murders in Kalamazoo and St. Joseph Counties.
Newschannel 3 spoke with one of Patten's close friends after new police reports revealed what likely sparked the attacks.
Patten is father to three young children. He lost custody of them when he and his wife divorced, and court records show the kids were often a flash point that led to threats.
But Patten's friend Mike Burnett wants others to know he wasn't a monster.
In the months, weeks, and days before police say Zachary Patten went on a deadly shooting spree, he was in controversial custody talks with his ex-wife about visits with his three young daughters, ages 16, 11, and 5.
Burnett describes Patten as a loving father.
"I always knew him as a level-headed, easy going. Always had a smile on his face. Always joking. So it really caught everybody I know off guard," Burnett said.
But newly released police interviews paint a different picture of Patten.
On the night of the shooting, his girlfriend says he came home from work in a bad mood.
He eventually left the house with a bag packed with clothes. Before he left, his girlfriend says she reminded him he had a custody hearing the next day. To which he replied, "I'm probably not even going to need court."
Just hours later, police say he went on to shoot and kill the sister of his girlfriend's ex-boyfriend, Graciela Portillo-Esparza, in Kalamazoo.
"I just assumed that after that he went to go see his kids, because he knew he messed up and he knew he was going to have to face the punishment for it," Burnett said.
From there, Police say patten raced off to the home of his ex-wife and mother of his three kids, where he shot and killed her husband Shane Richardson.
A friend of Richardson told police an officer then called him, telling him he was on a hit list that Patten had made.
He feared for the safety of his family, and planned to flee to an undisclosed location in Allegan County.
According to Saint Joseph County court records, during a custody battle Patten's ex-wife said he had bipolar disorder, where "he can be extremely agreeable, but in those other times he is extremely angry, vulgar, and threatening."
In one message, he tells his ex-wife to "please die."
During a police interview, Patten's girlfriend and daughter both mentioned the men Patten targeted late last month had previously said things to upset him.
"He's not a monster. I know what he did was wrong and it's a terrible thing. But he's not a monster. He's not going to get to see his kids anymore," said Burnett.
During a police interview on the night of his shooting spree, Patten said he was feeling like he was in a slump, and that issues with the men he targeted had been building up for months.