Dennis Creaghan Dennis Creaghan is the British actor who portrayed Louis in the fourth season episode in . Born in London , England , UK , Creaghan appeared throughout the 1980s in episodes of " Philip Marlowe , Private Eye " ( 1983 , with Kathryn Leigh Scott ) , " Reilly : Ace of Spies " ( 1983 ) , " Bergerac " ( 1985 ) , " A Very British Coup " ( 1988 ) , " Matlock " ( 1989 , with Steven Anderson and David Froman ) , and " The Young Riders " ( 1989 , with Brett Cullen , Yvonne Suhor , and Anthony Zerbe ) . His film credits include the television drama " Strong Medicine " ( 1986 , with Ben Cross , Alan Oppenheimer , and Daniel Benzali ) , the television drama " Murrow " ( 1986 , with Kathryn Leigh Scott ) , the thriller " Dream Lover " ( 1986 , with Joseph Culp ) , the television drama " The Ted Kennedy Jr . Story " ( 1986 ) , the comic adaptation " Superman IV : The Quest for Peace " ( 1987 ) , the television thriller " Breaking Point " ( 1989 , with Corbin Bernsen , Lawrence Pressman , and Ken Jenkins ) , and the action film " Prime Target " ( 1989 , with David Soul , Richard Cansino , and Mike Starr ) . Creaghan had guest parts in episodes of " Jake and the Fatman " ( 1990 , with James Sloyan ) , " Glory Days " ( 1990 , with Robert Costanzo ) , " Dragnet " ( 1990 , with Lenore Kasdorf , Diane Moser , Jimmy Ortega , and Marcelo Tubert ) , " L . A . Law " ( 1990 , with Corbin Bernsen , Larry Drake , Jennifer Hetrick , Concetta Tomei , George Hearn , John Glover , Diana Muldaur , and Frank Novak ) , " Murphy Brown " ( 1991 ) , " Civil Wars " ( 1991 , with Matthew Faison , Barry Kivel , and Gail Strickland ) , " NYPD Blue " ( 1994 , with Gordon Clapp , Sharon Lawrence , Louis Giambalvo , and Daniel Benzali ) , " The Client " ( 1995 , with Neal McDonough , Natalia Nogulich , John Pyper - Ferguson , Timothy Carhart , Anne Haney , and Angela Paton ) , " Diagnosis Murder " ( 1996 , with Peter Vogt and Michelle Bonilla ) , and " Murder , She Wrote " ( 1996 , with Richard Beymer , Meg Foster , Richard Libertini , and Tracy Middendorf ) . In 1995 he had the recurring role of District Attorney Jack Collins in five episodes of the drama series " Central Park West " , starring Mädchen Amick . Creaghan was also featured in the science fiction comedy " Project : ALF " ( 1996 , with Miguel Ferrer , John Schuck , Dell Yount , Erick Avari , Ed Begley , Jr . , Ray Walston , Lee Arenberg , Randy Oglesby , and F . J . Rio ) and the science fiction adventure " Robo Warriors " ( 1997 , with James Lew and Bernard Kates ) . Further television work includes the television series " Dark Skies " ( 1997 , with Jeri Ryan and Conor O ' Farrell ) , " Murder One " ( 1997 , with Barbara Bosson , Clayton Rohner , Jack Kehler , Alexander Enberg , Ellen Albertini Dow , Jack Blessing , John Fleck , and Richard McGonagle ) , " Total Security " ( 1997 , with Tony Plana , John Billingsley , Barbara Bosson , and Christopher Michael ) , " Cracker " ( 1997 , with Carolyn McCormick , Raymond Cruz , and Jack Blessing ) , " The Practice " ( 2000 , with Christine Healy , John Carroll Lynch , Vyto Ruginis , Harley Venton , Christopher Darga , and Ellen Geer ) , " Brooklyn South " ( 1997 , with James Sikking , Titus Welliver , Mark Kiely , Jana Marie Hupp , and Jack Blessing ) , and " Law & Order " ( 1993 , 1998 , and 2001 , with Carolyn McCormick , Fritz Weaver , Gail Strickland , Nicole Orth - Pallavicini , and John Berg ) . Following featured parts in the television thriller " Mr . Murder " ( 1998 , with Julie Warner , Bill Smitrovich , K Callan , Don McManus , Bertila Damas , Richard Riehle , Stephanie Niznik , Barbara Tarbuck , Greg Grunberg , Jim O ' Heir , Dell Yount , David Spielberg , and Jim Beaver ) , the television drama " Inferno " ( 1998 , with Stephanie Niznik , Tucker Smallwood , and Stoney Westmoreland ) , the romance " The Other Sister " ( 1999 , with Linda Thorson and Stephen Blackehart ) , and the remake " The Thomas Crown Affair " ( 1999 , with Fritz Weaver , Mark Margolis , James Saito , and J . Paul Boehmer ) , Creaghan appeared in episodes of " Ed " ( 2001 , with Jana Marie Hupp , Mike Starr , and Crystal Allen ) and " Third Watch " ( 2002 ) .