Dennis Booker is a character from the 21 Jump Street show. He was portrayed by Richard Grieco.
He is assigned to Jump Street in the Autumn at the beginning of Season 3. According to Doug Penhall, Booker is sent by Internal Affairs to investigate the feasibility of Jump Street.
Tom Hanson has to work with Booker on a Hate Crime Investigation which revealed that Booker is an open bigot. He said that Tom is a hypocrite by enjoying the luxuries of The West.
In Episode 4, Booker is assigned to work with Doug Penhall to inspect the safety of Football and to help make sure that Doug is not carried away. They conveniently played the role of Brothers. Still in character, Booker tried to bond with Doug. Doug walked away revealing that Booker himself wanted to be friends.
Grieco reprises his role for a cameo during the end credits of 22 Jump Street in the mock sequel entitled Jump Street: Generations.
The sequel also stars Dustin Nguyen (who portrayed Harry Truman Ioki on the TV series) although he only appears on the poster.
Nguyen, however, did have a cameo as Vietnamese Jesus during Jenko and Schmidt's WHY PHY trip where he appeared on Jenko's "good" side of the trip.
Dennis once went undercover as a radio host in the 21 jump street episode: Next Victim
Two of his former colleagues were involved in arms smuggling to gangs so a war between them would be prolonged as part of a plant of a tycoon to build a stadium. In order to crack the case, he broke rules, for which he was forced out of the police. The event did cost one of them his life, while he had to put the other one in jail. The tycoon got away. He swore revenge against the tycoon for his role in the events and succeeded with the help of his former colleagues at 21 Jump Street.
In 1989, Dennis Booker became the main character of the TV series Booker, a spin-off of 21 Jump Street.
Dennis explains why he doesn't like Chinese food, why he has a scar on his knee and what his nickname was as a kid in the 21 jump street episode: Nemesis
He said it's because he "found a worm in a egg roll."
His nickname when he was a kid was :Joe Cool
He got the scar on his knee from falling off his bike.
He is often smoking cigarettes throughout the 21 Jump Street show, although he claims he's been trying to cut back.
He and Tom Hanson often don't get along and are constantly arguing.