John Diehl born May 1 1950 is an American character actor with over 150 credits to his name in film and television He is best known for his roles as Charles Kawalsky in the 1994 film Stargate Det Larry Zito on the 1980s cop show Miami Vice Assistant Chief Ben Gilroy on The Shield and as the Cruiser in Stripes His other notable roles include Pvt Bucklin the spokesman of the 2nd Maine mutineers in Gettysburg Cooper in Jurassic Park III 2001 as G Gordon Liddy in the Oliver Stone movie Nixon the Klansman informant Mickey Mouse in A Time to Kill and as Keith a credit card company supervisor in Mo Money He also appeared as the spirit of Harley Earl in a series of commercials for Buick He was born in Cincinnati Ohio and graduated from St Xavier High School in 1968 For a time he flirted with a professional boxing career leaving Miami Vice to pursue it