Mekhi Phifer is an American actor. He portrayed Dr. Greg Pratt on NBC's long-running medical drama ER and had a co-starring role opposite Eminem in the feature film 8 Mile. He was a regular on the Fox crime show Lie to Me in the role of Ben Reynolds before season three, and also starred as CIA agent Rex Matheson in Torchwood: Miracle Day.

In 1994, Phifer attended an open-casting call for director Spike Lee's Clockers, beating over a thousand others to get the lead role as a narcotics dealer embroiled in a murder cover-up. He followed that role with another in the comedy spoof feature High School High (which also starred his former wife Malinda Williams) and continued by co-starring in the horror film I Still Know What You Did Last Summer, starring Jennifer Love Hewitt and Freddie Prinze, Jr.

He portrayed Dr. Gregory Pratt on the medical drama ER, which he started in April 2002. Phifer left the show in September 2008, in the first episode of Season 15. His character died during the conclusion of the season 14 finale cliffhanger involving an ambulance explosion that was rigged to kill an injured FBI informant (Steve Buscemi). During his six years in the show, he was nominated twice for an NAACP Image Award.

Phifer's television credits include the movies The Tuskegee Airmen (1995), HBO's Subway Stories: Tales from the Underground (1997), and Brian's Song (2001) (as former Chicago Bear Gale Sayers). He received additional notice for his performance opposite singer Beyoncé Knowles (from Destiny's Child) on MTV's alternative take on the Carmen legend with the movie Carmen: A Hip Hopera (2001). Phifer had a recurring guest role in Seasons 5 and 6 of Homicide: Life on the Street, portraying "Junior Bunk", the troubled nephew of Baltimore drug lord Luther Mahoney, and also guest-starred in New York Undercover. Likewise, he earned an NAACP Image Award nomination for another TV movie, A Lesson Before Dying, opposite Don Cheadle. In 2009, Phifer began a guest-starring arc on the Fox drama Lie to Me.

Among Phifer's other big-screen credits are Soul Food, The Biography of Spud Webb, Hell's Kitchen, NYC, Tears of a Clown, O (as the titular character Odin a.k.a. O), and the thriller Uninvited Guest (as Silk). He appeared in Impostor as well as Paid in Full, an urban classic, that has given him notorious recognition as he portrayed Mitch and director Curtis Hanson's 8 Mile, opposite Eminem. He is mentioned in the Grammy- and Academy Award-winning song "Lose Yourself" by Eminem.

In June 2011, Phifer starred alongside John Barrowman and Eve Myles as CIA agent Rex Matheson in Torchwood: Miracle Day, the fourth series of the BBC/Starz Entertainment television show Torchwood.

Phifer starred as Agent Collins in the fourth season of White Collar.

Phifer made a guest appearance on the sitcom series Husbands in its second season. In fall 2016, he joined the TV series Frequency as a series regular.

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