Leslie Nielsen actually appeared in a few episodes of the TV series The Fugitive (1963), which, of course, inspired the Harrison Ford movie The Fugitive (1993), which this film parodies.
Stay and read through the credits for some gag credits, like the Lottery Numbers, the Menu of the Day, "Interns We Had Sex With", "Things That Were Stolen", "People In Crew Who Smuggled Cuban Cigars Out Of Canada" and "People Nobody Cares About" (sped up), among others.
The Credits end with "Movie's Done".
When Ryan jumps away from the bus as it gets hit by a train, Ryan lands on a bicycle that doesn't have a seat. In the movie The Naked Gun 2 1/2: The Smell Of Fear, Frank Drebin tells Hapsburg that the truth hurts but not as much as jumping on a bicycle with no seat.
The detective that was given the blood sample at the original crime scene is addressed as Van Adder, a reference to the lead detective from the OJ Simpson trial. Also, he's told not to walk around with it all day, a reference to the OJ Simpson investigation in which a blood sample was left in a police vehicle all day and spoiled due to the heat.