(written from a Production point of view)
In the 1980s, he had a recurring role as Stanton on Crime Story. Bill Smitrovich was a regular on the show. He acted in the 2000 motion picture Space Cowboys, that also featured James Cromwell. Halligan also made appearances in Playing by Heart, The Island, When the Bough Breaks (with Ron Perlman) and Quick Change.
He has made guest appearances on many other popular shows, such as NYPD Blue, ER, The X-Files, Alias, Lost, Mad Men and Pretty Little Liars.