Joe was secretly hired by the evil and certifiably insane Nurse Claiborne to infect kids with Pinkeye in exchange for her delicious crumbles (which turned out to be made from Pinkeye crust). When Numbuh 2 started investigating the epidemic and suspected Joe, Joe was shot before he could reveal any information. Later, he saved Numbuh 2 from Nurse Claiborne, being shot again and badly injured in the process. After this incident, Joe was fired from the Hall Squad for his corrupt activities, and afterwards worked at a store owned by his father as a parking attendant.
Numbuh 2 visited Joe's dad's store to get chocolate sauce for the Sanban Family, and Joe briefly suspected him of stealing the sauce. When Numbuh 2 insisted he left money on the counter, Joe sent his assistant Stewie inside. Subsequently, when he heard a scream, Joe accused Numbuh 2 of having an accomplice before the Spankenstine Monster burst from the store. Joe responded by firing a water balloon at it but the monster retaliated by spanking and slapping him away. Joe later recovered and caught up to both Numbuh 2 and the Spankenstine Monster at the power substation just as the two were making up, shooting at it again, forcing the monster against the transformer, causing an explosion that reverted the monster to its inanimate Rainbow Monkey form.
Joe later turned up at the Sanban house, telling Mr. Sanban that he wished to issue an apology to Numbuh 2, having confirmed that he indeed left money on the counter and hands over the sauce only for Mr. Sanban to seize the can and slam the door in his face.
Sometime later, after striking a deal with a nerdy safety patrol member - known as Crayon Boy - Joe was reinstated into the Hall Monitor force, as seen in this episode.
- His name is a pun on the comic strip character Joe Palooka.
- He may have feelings for Numbuh 3 because when she (pretending) said, " I should have never fallen in love with you!", in Operation: C.R.I.M.E., his eyes got big and he almost got emotional.
- During his first appearance in Operation: P.I.N.K.E.Y.E. he and Numbuh 2 shared a fondness for Nurse Claiborne's crumbles (until they found out what the topping was); then he switched over to lollipops in S.P.A.N.K.E.N.S.T.I.N.E. and C.R.I.M.E. The lollipop is a reference to the habitual usage that cigarettes were in old detective movies, changed here for a more kid-friendly approach.
- His hair grows longer in each episode he appears in.