Story highlights Joseph Boston is charged with 2 counts of oral copulation on a child under 10

Police say Boston admitted molesting dozens of children over 8 years

(CNN) It was 3 in the morning, and a California woman was attempting to flag down a police officer; she wanted to report that her son just told her he had molested two boys.

The confession would go much deeper once Riverside police detained 18-year-old Joseph Boston on Saturday, authorities say.

Not only did he confess to sexually assaulting 4- and 8-year-old boys at a $65-a-night motel room about a mile away from the police station, but he also admitted molesting "upwards of 50 children since he was 10 years old in different cities where he had lived," according to Riverside police.

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Those previous addresses include the Southern California cities of Lakewood and Buena Park, police said. Boston had been staying in Riverside, about an hour's drive east of Los Angeles, since earlier this month.

Boston had a room at the motel where he "befriended" the boys, who were staying with their parents, also guests at the motel, a police news release said. The children went to Boston's room Friday night, the statement said.

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