He got the supporting role of Lieutenant Guilford, a southern Navy officer and spy hunter in the TNT made-for-television film Ironclads opposite Actress Virginia Madsen and actor Alex Hyde-White in (1991).Having become an established supporting actor, he earned his first ever starring role, in the CBS biographical television miniseries Sinatra as the title character singer Frank Sinatra opposite Oscar-winning Actress Olympia Dukakis in (1992). The series earned him further recognition for his acting talents even gaining attention from the Hollywood Foreign Press Association snagging a Golden Globe award nomination for Best Lead Actor in a Miniseries or Television Film for his performance - a first throughout Casanoff's acting career.He returned to the big screen in the romantic comedy/drama film Jersey Girl as Mitchell opposite Actress Jami Gertz and actor Dylan McDermott in (1992).He had a minor role as Detective Battaglia in the crime/drama film Saints and Sinners in (1994).He returned to television in the short-lived CBS police drama series Under Suspicion in the recurring role as Internal Affairs Sergeant Jimmy Vitelli opposite Actress Karen Sillas in (1994-1995).He guest starred on the CBS medical/drama television series Chicago Hope as Paul Accosta episode "Chrismas Truce" (1995).He guest starred on the CBS sitcom The Nanny as Cantor Gary Isaacs re-teaming with Actress Fran Drescher episode "The Cantor Show" in (1996).He guest starred on the NBC sitcom Wings as Eric episode "Too Beautiful for You" in (1996).He guest starred on the CBS drama series Promise Land as Bill Carter opposite actor Gerald McRaney episode "Little Girl Lost" in (1996).He co-starred in the Lifetime made-for-television movie Little Girls in Pretty Boxes as Greg Radkin based on the novel by Joan Ryan. It portrayed a fictionalized account of a teenage girl whose family relocates to Los Angeles, California to pursue Olympic Gold with a difficult coach and rigorous schedule, drawing on many of the stories Ryan recounts in the book.He guest starred on the British/Canadian Sci-Fi Channel horror/anthology series The Hunger as william Cobb episode "Necros" in (1997) presented by actor Terence Stamp in (1997).He appeared in the ABC made-for-television film Tempting Fate as Dr. Bardwell starring actor Tate Donovan in (1998).He returned to the big screen in a minor role as Kennedy in the romantic comedy film How Stella Got Her Groove Back starring Actress Angela Bassett in (1998).He had another minor role as Cortez, IBI Chef in the CBS sci-fi/action made-for-television film Chameleon starring actor Bobbie Phillips in (1998).He made a guest appearance on the NBC medical drama series ER as Dr. Dan Litvak episode "Masquerade" opposite actor George Clooney in (1998).He guest starred on the short-lived ABC revival drama series Fantasy Island episode "Innocent" starring actor Malcolm McDowell in (1999).He made a guest appearance on the ABC legal drama series The Practice as Danny Rogers episode "Of Human Bondage" re-teaming with actor Dylan McDermott in (1999).He guest starred on the CBS crime/action series Walker, Texas Ranger as Harris episode "Livegirls.now" starring actor Chuck Norris in (1999).He made a guest appearance on the CBS comedy/mystery/medical/crime-drama series Diagnosis Murder as Grant Conner episode "The Seven Deadly Sins" starring actor Dick Van Dyke in (1999).He made his third return to television on the HBO drama series Oz in the recurring role of Nikolai Stanislofsky from (1999-2000).