Horatio Vallejo (commonly referred to as Vallejo or Jr. Commissioner Vallejo) is the Mexican-American junior commissioner of the X Middle School Safety Patrol. Once a regular patroller (much like Fillmore) Vallejo is a strong, supportive and rather strict leader, although he does usually show a softer side. Vallejo's catchphrase is yelling "FILLMORE!", which he does in almost every episode when he hears of something Fillmore broke, like a waxer, and ordering expensive walkie-talkies by tricking him in to signing his signature. He is voiced by Horatio Sanz.
Before becoming Junior Commissioner, Vallejo was a regular safety patroller who had a lot of rough experiences with partners as results of varying missions. Two of his known partners were Malika (who became the ruthless leader of the Red Robins) and Frank Bishop (a profiler who was discharged from the force by Principal Folsom).
As Junior Commissioner, Vallejo is in charge of making sure that the job gets done and that the safety patrollers work within restrictions (although Fillmore usually causes him hassle by causing destruction and therefore receiving repair bills). In The Shreds Fell Like Snowflakes, Vallejo was awarded his second term as Junior Commissioner by Principal Folsom.
Although, calm-natured most of the time, Vallejo can be quick to anger who can sometimes make rash decisions. During one point of series, Vallejo had a large addiction to cocoa and enjoys various sandwiches from vending machines around the school. Vallejo has a deep sense of care for the upholding of the school rules and wants all cases to be solved as soon as possible (especially with Principal Folsom making strict demands).
Vallejo is rarely seen during missions and does not appear to show many skills apart from leading his teams. However, it can be assumed that his investigatory skills are recognized as being the best in the current Safety Patrol.