(CNN) -- Leon Walker, a Detroit, Michigan, computer technician, faces a jury trial in February for allegedly hacking into his then-wife's e-mail account.
"She'd asked me to read her e-mails before," Walker said in an interview this week. "She gave me the password before. She didn't hide it."
Walker says the e-mails revealed that Clara Walker, who has been married three times, was having an affair with her second husband.
Walker, the third husband, shared the documents with his wife's first husband, who then used them to file an emergency motion to obtain custody of his son with Clara Walker. Leon Walker said he and the first husband were both concerned because, according to Walker, husband No. 2 had a prior arrest on a domestic violence charge.
"He took action with the courts to have himself protected and I took action with the court to have my daughter protected," Walker said.
When Clara Walker learned how the e-mails made their way into court, she complained to police.
Oakland County, Michigan, Prosecutor Jessica Cooper used a state anti-hacking law to charge Leon Walker with a felony.
Cooper did not immediately respond to CNN calls for comment, but the Detroit Free Press published a voice-mail from her.
"The guy is a hacker," Cooper told the newspaper. "It was password protected, he had wonderful skills, and was highly trained. Then he downloaded them and used them in a very contentious way."
The Michigan statute forbids someone from accessing "a computer program, computer, computer system or computer network" to acquire property "without authorization."
New York criminal defense lawyer Paul Callan said all 50 U.S. states have such laws, but he called this "a highly unusual use of a criminal statute."
The laws are typically used to prosecute "some technological guy who's broken into a company's computer system and damaged it or stolen something," Callan said.
Leon Walker's defense lawyer agreed.
"I find it so hard to believe that our legislature would enact a law and say 'You know what, if husbands and wives are reading each others' e-mail, that's a priority for us and we've got to stop that,'" attorney Leon Weiss said.
Walker said his decision to peek into his wife's e-mail account was like someone kicking in a door to save someone from a burning house.
"Do you kick the door open or do you let it burn?" Walker said. "I did what I felt was absolutely necessary."
Clara Walker responded in a written statement submitted by her attorney, saying "Leon is not the saint portrayed in the media."
"If you believe news reports you would think he was the faithful husband looking to protect my children. Nothing could be farther from the truth," she said.
The couple's divorce was finalized earlier this month.
CNN's Julie Cannold contributed to this report.