"Everybdy makes mistakes," the tweet read. "I was out of charcter & ive grown sense then Dont judge me for my past i can admit my wrongs and I apologize.#3hunna."
The apology came days after the video was posted online, the Chicago Sun-Times reported Sunday.
The video shows a young woman inquiring who let a group of young men into a home. She begins to argue with a young man, purported to be Lil Reese, who then gets close to the young woman and starts punching her.
Chicago police said they were not actively investigating the beating because they don't know who the victim is, when the incident occurred or where.
Lil Reese, whose real name is Tavares Taylor, is a 19-year-old rapper for Def Jam Recordings.
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