Mark O'Mara is one of five siblings in a Roman Catholic family of Irish descent. He was raised in Rosedale, Queens, New York City. His father, John Joseph O'Mara, was a World War II veteran, shot down over Germany and spent the better part of a year in a POW camp, until liberated by the Soviets. His father came back to Brooklyn and married his fiancée, Anna "Nancy" McAteer.[7] John Joseph O'Mara joined the New York Fire Department, where he rose to Battalion Chief. He was also President of the Fire Officers Union before he retired and moved to Orlando, Florida, bringing his wife and youngest son Mark, with him.[8][9]
O'Mara was an Assistant State Attorney with the Seminole County State Attorney Office from 1982 to 1984. Mark M. O'Mara started his career as a prosecutor for the State Attorney's office in Seminole County [5], then began his private practice, joining forces with other local attorneys before beginning his own firm... Mark is one of only a few lawyers in Florida who are Board Certified in both Criminal Trial Law and Marital and Family Law; he is also certified in Collaborative Law and is a Supreme Court Certified Family Mediator and Circuit Civil Mediator. He has practiced in both state and federal courts throughout the nation, often co-counseling for complex trials and civil rights matters.[12]
He has recently expanded his practice to include representing clients aggrieved by large corporations, from drug and medical device manufacturers to automobile companies in an area of law known as Mass Torts. He and his team utilize the research and trial presentation skills honed over thirty-six years to hold these companies responsible for their wrongs, and to make them more responsible in their future behavior.[11]
O'Mara was a legal analyst for WKMG Channel 6, an Orlando, Florida television station.[13][14][15] After the Zimmerman case was over, he was hired as a legal analyst by CNN, a position he has held for over two years.
In September 2013, after a domestic altercation between George and Shellie Zimmerman, O'Mara said he was continuing to represent George Zimmerman in a defamation lawsuit against NBCUniversal but was not representing him in the "domestic altercation case or his impending divorce case".[17]
^Julie Bosman and Monica Davey (November 22, 2014). "In Ferguson, Preparation and Anticipation as Grand Jury Decision Nears". The New York Times. Retrieved November 25, 2014. 'This is a unique grand jury to begin with,' Mark O'Mara, the criminal defense lawyer who represented George Zimmerman in the killing of Trayvon Martin in Florida, said in a telephone interview.
^"Zimmerman's new attorney: Who is Mark O'Mara?". NBC News. April 12, 2012. Retrieved November 25, 2014. The central Florida defense attorney and former prosecutor has nearly 30 years of experience under his belt, representing clients in criminal cases ranging from drunk driving to the death penalty.
^Ray Sanchez (November 24, 2014). "What's next for Officer Darren Wilson?". CNN. Retrieved November 25, 2014. "It would be senseless for him to go back to Ferguson," CNN legal analyst Mark O'Mara said.
^"Zimmerman's new attorney: Who is Mark O'Mara?". NBC News. April 12, 2012. Retrieved November 25, 2014. He also has clocked time in front of the television cameras, serving as a legal analyst for local station WKMG Channel 6, where he commented on high-profile cases, including the Casey Anthony case and even the Martin one – before he was hired to represent Zimmerman.
^"Local 6 legal expert Mark O'Mara now representing George Zimmerman". WKMG Channel 6. April 11, 2012. Retrieved November 25, 2014. Attorney Mark O'Mara, who was a legal expert for Local 6 in the Casey Anthony murder trial and the ongoing Trayvon Martin death investigation, is now representing George Zimmerman, the neighborhood watchman who shot and killed the teen in Sanford.
^Oren Dorell (April 12, 2012). "Zimmerman defense lawyer not new to spotlight". USA Today. Mark O'Mara is known to central Florida residents because he appeared often on Orlando television station WKMG as a legal analyst during the trial of Casey Anthony, the Florida mother acquitted in July in the death of her 2-year-old daughter, Caylee.