However, Govich proved to be even more unpopular with fans than her predecessor was and left the show after one season with the explanation being that Detective Cassady's assignment to the precinct had been temporary and had been transferred out. She was replaced by Jeremy Sisto, who had previously guest starred as a defense attorney in the season 17 episode "The Family Hour", as Detective Cyrus Lupo. Around the same time, Thompson announced he would leave the show to seek the 2008 Republican presidential nomination. (No explanation was given within the show regarding Arthur Branch's off-screen departure.) Waterston's character was promoted to Interim District Attorney (later made full District Attorney in season 20) and his former position was filled in by Executive Assistant District Attorney Michael Cutter, played by Linus Roache.
However, Govich proved to be even more unpopular with fans than her predecessor was and left the show after one season with the explanation being that Detective Cassady's assignment to the precinct had been temporary and had been transferred out. She was replaced by Jeremy Sisto, who had previously guest starred as a defense attorney in the season 17 episode "The Family Hour", as Detective Cyrus Lupo. Around the same time, Thompson announced he would leave the show to seek the 2008 Republican presidential nomination. (No explanation was given within the show regarding Arthur Branch's off-screen departure.) Waterston's character was promoted to Interim District Attorney (later made full District Attorney in season 20) and his former position was filled in by Executive Assistant District Attorney Michael Cutter, played by Linus Roache.