The 6-foot-1, 175-pound Brown originally was going to sign with Arizona, but he altered his plans after Wildcats offensive coordinator Sonny Dykes left to become the head coach at Louisiana Tech.
"Odds of going to TCU are at 90 to 10 right now," Brown told ESPN affililiate WildcatSportsReport.com. "I just think TCU is better for me and my family."
The Horned Frogs also received a verbal commitment from three-star WR Chris Hawkins of Channelview. The 6-1, 165-pound wideout, who originally had picked Minnesota, had 27 catches for 656 yards and 10 TDs last season.
Texarkana's Antonio Graves, who played quarterback but is being recruited as an athlete, also has accepted an offer from TCU after decommitting from Louisiana Tech.