A disturbed “homeless drifter” with a long rap sheet has been arrested in the murder of a 14-year-old Florida schoolboy who was found dead after going for a bike ride last month, police announced Thursday. Semmie Lee Williams, 39, was arrested in Miami late Wednesday in connection to the murder of high school freshman Ryan Rogers, authorities confirmed at a press conference. The teen was found dead on Nov. 16 on Central Boulevard near the Interstate 95 overpass in Palm Beach Gardens — and his death quickly ruled a “deliberate act.” It “appears to be a completely random act” with no apparent motive, the chief said. “I would best describe it as an innocent child victim having a chance encounter with a very violent criminal,” Shannon said, calling Williams a “homeless drifter.” Palm Beach Gardens police chief Clinton Shannon said that the teen had been “stabbed to death” by a “dangerous monster.” Williams’ DNA was then found at the murder scene, and his YouTube videos — which often show him ranting disturbing conspiracy theories — put him in the area around the time of the murder, The Miami Herald said. Those same online videos helped investigators track him down to Miami, the paper noted. He was tracked down on Friday, but committed to a hospital under Florida’s Baker Act, which allows for the involuntary commitment of someone who is a danger to himself or others, the report said.