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Lesley McSpadden and Michael Brown Sr., the parents of slain 18-year-old Michael Brown, acknowledge a crowd during an event at the Greater Grace Church on Aug. 17, 2014, in Ferguson, Missouri. Getty Images

The mother of Michael Brown, the unarmed black 18-year-old whose fatal police shooting last August launched riots in Ferguson, Missouri, linked white Officer Darren Wilson to the devil in a TV interview scheduled to air Wednesday night. Lesley McSpadden told Al Jazeera America that Wilson was cold and malicious for shooting her son in the street, according to a transcript of the episode.

“The devil. That comes to mind. Evil," McSpadden said. "He wouldn't even admit what he did was wrong. He wouldn't admit he had no reason to do what he did ... I'll never forgive him."

Wilson fired at Brown 12 times on after allegedly being confronted by Brown on a residential street Aug. 9, 2014. The officer later testified before a grand jury that he feared for his life, but the sequence of events that day remained unclear -- some witnesses argued Brown hadn't been doing anything wrong and put his hands up when he spoke to Wilson. After a lengthy investigation and deliberation, the grand jury decided in November not to indict Wilson for Brown's death. It set off a second wave of protests in Ferguson, where residents said police regularly abused them based on race.

Wilson went silent after he resigned from the Ferguson Police Department. But he opened up recently for an anniversary story published this week in the New Yorker. Wilson said he'd encountered trouble trying to find a new job and mentioned a "pre-gang culture" that existed in Ferguson.

He repeated his account that Brown had tried to kill him and complained about the civil wrongful death suit Brown's family filed against him in April. "Do I think about who he was as a person? Not really, because it doesn't matter at this point," Wilson said. "Do I think he had the best upbringing? No. Not at all."

McSpadden fired back on Al Jazeera America, calling the New Yorker article a waste of an interview. Brown wasn't in a gang and didn't have enemies, she said. “What [Wilson is] talking about, he has no idea about my life at all," McSpadden added. "He had no idea what he was taking away when he did that to my son."

The mother went on to say she thought the non-indictment had "of course" been part of a cover-up. But she said her son didn't die in vain because it inspired a powerful social movement that's turned out protesters across the country to stop institutionalized racism and police brutality.

"This fight isn't just a fight. It's like a war. And in war, you have troops," McSpadden said. “[The war is to] make people like him understand that saying that has become popular about black lives. They have to say that. They have to know that. We know that we matter. They need to know that we matter.”