Watsonville police have arrested a man accused of filming himself sexually assaulting at least two children.Travis Hernandez, 24, was arrested at his apartment on Blackburn Street on Monday, according to police. This case was forwarded to the Watsonville Police Department after the Silicon Valley Internet Crimes Against Children Task Force received an online tip of suspicious activity on Hernandez's Google account from the National Center for Missing and Exploited Children.Watsonville detectives worked alongside members of the ICAC task force and found that Hernandez had produced child pornography while sexually assaulting at least two children on separate occasions. While being interviewed, Hernandez admitted to sexually assaulting both children shown in the videos, according to police.Both victims have been identified. Hernandez was booked into the Santa Cruz County Jail on Monday night and is being held without bail because of a prior felony conviction. He is facing multiple charges of producing child pornography and child sex assault. Hernandez is expected to make a court appearance Thursday morning.Police say this is an active case and at this time, they do not know if there are additional victims.Anyone with information on this case is asked to call Detective Rudy Lopez at 831-768-3357 or Detective Nelson Hernandez at 831-768-3358.