Arsenio Baldizon

 is a minor character featured in Red Dead Redemption.

Background
Arsenio appears to be an officer in the Mexican Army.

Red Dead Redemption
Arsenio can often be seen patrolling Escalera, El Matadero, or El Presidio. However, if Marston has a bounty, Arsenio will track him to multiple locations around Nuevo Paraiso.

Undead Nightmare
In Undead Nightmare, Arsenio can be found patrolling El Presidio and commanding the soldiers there.

Trivia

 * After Abraham Reyes overthrows Colonel Agustin Allende, Arsenio will disappear.