HA! I should have scrolled down deeper into that Wikipedia article. Here's more...
"Denny is a staunch conservative Republican. He actually voted for Barack Obama in the 2008 election, but he refuses to admit it publicly, except to Alan.
He strongly opposes gun control, claiming that "It's for communists." On the recommendation of his friend Tom DeLay, he keeps a wide variety of loaded guns in his office (including the camouflaged AR-7 he saved Alan with [1]).
On numerous occasions, Denny has accidentally discharged his guns, although no one has ever been hurt by his carelessness. However, he does have a fondness for using his gun(s) on living people, and has done so more than once. Denny first shot the aforementioned man who was threatening Alan with a gun right in the offices of Crane, Poole & Schmidt.[4] In another episode, he was forced against his will by a judge to provide pro bono representation to an accused child rapist/killer. The killer privately bragged to Denny about having committed the crime, and Denny responded by shooting both the man's kneecaps in "self-defense" with a gun he had smuggled past courthouse security in his briefcase.[5] He also shot a homeless man in the head with a paintball gun after the man threw a rock at his head because Denny ignored his pleas for spare change.[6] Finally, Denny shot his psychologist on two separate occasions: first in self-defense when the psychologist brandished a gun after Denny pulled his gun first, and then again in a courtroom after the psychologist was threatening to shoot Alan.[7] As Paul Lewiston put it best: "He [Denny] shoots people." When a concerned client and friend of Denny's accused Denny's firm of not being environmentally conscious, Denny opened fire on him with a paintball gun, and later shot him several times with an air soft gun during a subsequent meeting. He later shot Carl Sack with the same gun.[8]
In the fifth season, a criminal attempted to steal Denny and Jerry Espensons' wallets by holding them at gunpoint. As Denny hands his wallet over, he pulls out a gun and shoots the would-be mugger three times in the legs, leading Denny to be arrested for carrying a concealed weapon. Denny arranged for Jerry to give a strongly pro-gun closing argument, hoping to lose so that they could appeal the case to the Supreme Court as part of Denny's agenda to change gun laws; despite this, the jury finds Denny not guilty anyway. While on vacation in Utah with Alan, Denny - and Boston itself - are insulted by a man with a heavily accented New York accent, prompting Denny to shoot him in the knee with a tranquilizer gun, knocking him out."
Of course, we have the bias of the Wikipedia writer mixed in there... but...