He was in private practice in Buffalo from 1968 to 1969. He joined the office of the United States Attorney of the Western District of New York in 1969, first as an Assistant United States Attorney until 1973, then as a First Assistant United States Attorney from 1973 to 1974, finally becoming the district's United States Attorney from 1975 to 1981. He was then Erie County, New York District Attorney from January 1, 1982 to May 31, 1988.[1]
Arcara presided over the 2007 trial of James Charles Kopp, who was charged with violating the Freedom of Access to Clinic Entrances Act. Kopp had previously been convicted in 2003 in New York State court by Judge Pigott for the 1998 sniper-style murder of Dr. Barnett Slepian, an American physician from Amherst, New York who performed abortions. Judge Arcara also presided over the internationally significant Robert Rhodes trial in 2005. Rhodes, a United States Customs and Border Protection Officer, was arrested and indicted for beating a Chinese National on the US-Canada border in Niagara Falls, NY. The incident was addressed by then Secretary of State Colin Powell and Secretary of Homeland Security Thomas Ridge when the Chinese Foreign Minister accused the United States of human rights violations by Rhodes' actions. Rhodes was acquitted after a high-profile trial in August 2005, presided over by Chief Judge Arcara.[2][3][4]