"We heard a woman cry, like someone cry and we look over," said Woo.
"And this guy was running off. We went over there to help her. Ken chased after the guy," said Ford.
But another person who was on the street that day told police he saw something quite different: He didn't see the boys helping out. He said they were the muggers, reports CBS News Correspondent John Blackstone.
Police put the three in handcuffs.
"We thought we'd probably just be cuffed for a while, you know, handcuffed for a while until they figured things out," said Woo.
But police didn't figure things out because the victim spoke only Chinese. On the word of the bystander the teens were locked up.
"The information at the scene was more than sufficient to base an arrest upon," said Deputy Chief Clark Kimerer of the Seattle Police Department.
The boys' teachers were shocked.
"They're the nicest kids in the world. They're always helping other people. They're so respectful," said Anna Maria de la Fuente.
The shock grew when the three were held for trial with bail that appeared to be "color coded": $10,000 for Yi Ming, $20,000 for Ken, and $25,000 for Rico.
When police finally put a translator on the case the victim said the boys had helped her, not robbed her. Prosecutors dropped all charges
The boys have received neither an apology nor any refund for thousands in legal fees.