Mr. Freeman is Vivian's boyfriend and Maya's rapist.
Before the rape, Mr. Freeman's defining characteristic seems to be that he, um, doesn't do anything. Seriously. He doesn't talk, he doesn't read, he doesn't listen to the radio—he just sits there. Only when Vivian comes home does he show any action, and he jumps out of his chair to greet her.
Maya describes Mr. Freeman as a "big brown bear" (11.4). Let's think about that for a second. Bears are mostly quiet, cute, and cuddly looking—oh, and they hibernate for a long time. (Check.) But when they're awake, they can be extremely violent and dangerous. (Check.)
Mr. Freeman is an unlikely father figure for Maya. Although it's confusing for her, his physical touch makes her feel wanted. Considering that she felt rejected by her parents, and Momma's love is not the touchy-feely kind, it makes sense that she is deeply affected by his hug.
Why did Mr. Freeman rape Maya? We don't know. Did he feel guilty? We don't know. All we know is that his presence changed Maya's life forever.
After the rape is discovered, Mr. Freeman is killed (probably by Maya's protective uncles). But his death does not indicate the end of his influence on Maya's life—not by a long stretch.
After the rape, she takes a vow of silence, worried that her words can kill. Even once she begins speaking again, she is careful not to talk about St. Louis. The rape and the guilt that Maya has over his death haunt her life like a specter for nearly the whole novel—and, we can imagine, the rest of her life. For more on this, check out Maya's "Character Analysis."