Huaman is one of Peru's "forgotten" people, marginalized, rural groups Castillo tried to represent - often falling short - whose anger has been fired up by his arrest, threatening to derail a fragile new government and a reviled Congress.
Many of the protesters - some Castillo supporters and others simply angry - said they felt ignored by political leaders.
The military says protesters, most in Peru's Andean south, have used homemade weapons and explosives.
A political rookie, he had won support with pledges to reform the constitution, redistribute huge copper riches and empower marginalized indigenous groups.
Outside the Lima jail, Katherine Asto had come to support Castillo wearing a white hat with a slogan making her feelings clear: "Shut down Congress, it's a nest of rats".