McSpadden's comments to Al Jazeera followed an interview with Wilson published by The New Yorker, in which he admitted that, aside from ongoing litigation brought by the Brown family, he seldom thought of the 18-year-old Brown.
"Do I think about who he was as a person? Not really, because it doesn't matter at this point," Wilson said, before adding that he believed Brown didn't have a proper "upbringing."
McSpadden responded to Wilson’s comments by saying the officer was the one who "didn’t have the right upbringing."
"Because those are words that you just don't use, especially after you took somebody's life and you know you had no reason to," she said. "But he can't hurt me with his words. What he did last year hurt me really bad, so his words mean nothing to me."
Wilson, who scuffled with Brown before the shooting, told authorities that he feared for his life during the confrontation and fired his gun in self-defense. Witnesses, however, contend that Brown was in a nonthreatening position when Wilson fired the fatal shots.
A St. Louis County grand jury decided in November that there was not enough evidence to indict Wilson for murder, further inflaming protesters, who clashed with police and rioted on the streets of Ferguson. In March 2015, the U.S. Department of Justice also declined to prosecute Wilson for civil rights violations.
"I can't wrap my mind around it, and they can never get me to understand why it happened or how they came up with no indictment and the Department of Justice didn't see [Wilson] doing anything wrong with his job," said McSpadden.
She said she believes that St. Louis County prosecutor Robert McCulloch didn't fulfill the responsibilities of his position and wished that a special prosecutor had been appointed to handle the case.
"He did not think about my son's family, my son, how we were affected. He didn't think about any of that. He specifically said he would not recommend charges, and this is before even looking at all the evidence and taking it into consideration and really want to do your job the right way," McSpadden said. "I would have rather him left someone that wanted to do their job, do the job as a prosecutor."
The Brown family has filed a wrongful-death lawsuit against the city of Ferguson, Wilson and the city's former police chief Thomas Jackson. But last month, a federal judge dismissed several counts of that lawsuit — two of which were ruled redundant counts against Wilson and Jackson.
Talking about how the death of Brown has affected some of the younger members of her family, McSpadden said her 6-year-old daughter and 8-year-old nephew now run in fear whenever they see police officers.
"If they're out riding their bike or just out playing with some more kids, when they see a police, they run," she said. "And it's scary, because I would hate for these younger kids to grow up and be in a situation when they have to call on the police or they need some help and … for them not to have that as a necessity or access for them because they're so scared of what they witnessed."
Turning her attention to other recent high-profile incidents in which African-Americans were killed by police, including the cases of Freddie Gray in Baltimore and Samuel DuBose in Cincinnati, McSpadden said she wished to see justice.
"It's the same question … How many times are they going to allow it to happen and keep happening before they make an example out of one of these people who are taking people's lives?"