Officer Cavanaugh is a member of the Albuquerque Police Department.
Cavanaugh pulled over Walter White for having a cracked windshield. Walt wondered why Cavanaugh was giving him a ticket, considering that his windshield was damaged during the Wayfarer crash. Cavanaugh stated that Walt's Pontiac was unsafe to drive in, but Walt took issue with this. Cavanaugh ordered Walt to wait in his car while he went back to his, but Walt got out and started arguing with Cavanaugh that he shouldn't be cited for something that, to him, was out of his control. Cavanaugh told Walt to stand back, but Walt continued to get closer and more volatile, until Cavanaugh threatened Walt with pepper spray. However, this just made Walt angrier, saying that Cavanauagh would be pepper spraying an "innocent man" simply expressing his constitutional rights. Regardless, Cavanaugh pepper sprayed Walt and arrested him, throwing him in the back of his squad car.
Later, Walt was in custody while his brother-in-law, Hank Schrader, talked to Cavanaugh and his partner about Walt's recent misfortunes, and asked for them to cut him some slack. Walt then apologized to Cavanaugh, who let Walt go with Hank ("Caballo Sin Nombre").