About
Allen Mastantuno is a Charleston criminal defense and trial attorney with extensive courtroom experience. Born and raised in Charleston, he is committed to protecting the rights of individuals facing criminal charges and helping those injured in accidents. Known for his strong advocacy, he has defended clients in cases involving violent crimes, drug offenses, and financial crimes, while also representing accident victims in personal injury claims throughout the Charleston area.
Mr. Mastantuno earned his B.A. from the College of Charleston in 2003 before receiving his J.D. from the University of South Carolina School of Law in 2007. After graduation, he clerked for the Federal Public Defender’s Office in Charleston, where he gained experience in the federal criminal system. These early roles gave him valuable exposure to trial preparation, defense strategy, and client advocacy, providing a strong foundation for his career as a trial lawyer.
From 2008 to 2010, Mr. Mastantuno served as a prosecutor for South Carolina’s Ninth Judicial Circuit, covering Charleston and Berkeley Counties. He became the lead DUI prosecutor in Berkeley County, handling more than 100 DUI cases ranging from first offenses to felony DUIs involving death. In addition to DUI cases, he prosecuted serious crimes including armed robbery, burglary, and murder, gaining extensive jury trial experience and developing a reputation as a strong courtroom advocate.
Since 2010, J. Allen Mastantuno has focused exclusively on defending clients and representing accident victims. His criminal defense work includes charges of murder, attempted murder, arson, criminal sexual conduct, drug trafficking, and financial crimes. He also advocates for individuals injured in car, motorcycle, boating, and other accidents. With years of trial experience on both sides of the courtroom, he provides clients with informed strategies, determined representation, and a commitment to achieving the best possible outcomes.
Law Office Affiliations
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Founding Attorney, Mastantuno Law Firm, LLC
- Member, South Carolina Bar
Licensed State
- South Carolina
Education
- University of South Carolina School of Law
Juris Doctor (JD) - College of Charleston
Bachelor of Arts (BA)
Awards & Badges



- Drug Crime
- DUI & DWI
- Federal Crime
- Speeding And Traffic Ticket
- White Collar Crime




