Four horses were killed in a barn fire in rural Boulder County, Colorado, on Sunday, Oct. 1, 2017. Authorities are investigating the possibility it was arson. -- Photo courtesy of Janiejill Tointon.

UPDATE: Colorado Barn Fire Suspect in Custody

A man suspected of starting a barn fire last week that killed four horses, including three sons of Shining Lil Nic, is in custody in another state, officials say.