Mark Neff

Neff & Sedacca, P.C.

Sex Crime Lawyer | Serving Philadelphia, PA

Free Consultation

1845 Walnut Street, Suite 1300
Philadelphia, PA 19103

Criminal Defense Legal Representation

When choosing a Criminal Defense Lawyer in Philadelphia, you must consider the attorney’s reputation. At Neff & Sedacca, we have developed a reputation for the successful defense of serious criminal cases throughout Pennsylvania and New Jersey, and throughout the country by combining an unmatched record with dedication to their clients and attention to detail.

Contact us today if you need legal assistance with any of the following:

Criminal Defense

  • Domestic/Sex Offenses
  • Federal Crimes
  • White Collar Crimes
  • Cyber/Internet Offenses
  • DUI/DWI
  • Drug Offenses
  • Professional Licensure
  • Appeals/Post Conviction
  • PSEA Member Representation

Call Neff & Sedacca, P.C. today at 215-563-9800 to arrange your free initial consultation.

Attorney Mark Neff

Mr. Neff began practicing law in 1986 and has limited his practice to the area of criminal defense for more than three decades. As founder and managing partner of Neff & Sedacca, he leads a team of highly skilled associates, assistants and para-professionals including law clerks, research assistants, paralegals and investigators. The firm also maintains a network of expert witnesses that include drug experts, accident reconstructionists, DNA experts, forensic toxicologists, forensic pathologists, forensic accountants and others. Although based in Philadelphia, Neff & Sedacca represents individuals and corporations facing serious criminal charges across the United States and internationally. Mr. Neff has represented clients from a variety of backgrounds, such as corporate executives, entertainment personalities, medical and legal professionals, teachers, public officials and ordinary citizens – handling each case with the same level of concern and attention.

Organizations & Memberships

Mr. Neff is a member of the Pennsylvania, New Jersey and Philadelphia Bar Associations, the Philadelphia Trial Lawyers Association and Lawyers Club of Philadelphia. He is also actively involved with Pennsylvania Association of Criminal Defense Lawyers, Association of Criminal Defense Lawyers of New Jersey and National Association of Criminal Defense Lawyers. From 2005-2008, Mr. Neff served by appointment on the Supreme Court of Pennsylvania Criminal Procedural Rules Committee. Over the years, Mr. Neff has participated in a variety of lectures and speaking engagements, including various PSEA events.
Rising Star Super Lawyers: 2010 - 2019


Attorney Matt Sedacca

Mr. Sedacca has been practicing law since 2010 and over the years has worked on both sides of the courtroom. Prior to joining The Law Offices of Marc Neff, he began his career with the Philadelphia District Attorney’s Office. As an Assistant District Attorney, he handled thousands of cases in every aspect of the criminal justice process.

In 2013, Mr. Sedacca chose to cross the aisle, bringing with him an in-depth understanding of the complex workings in the criminal justice system along with a reputation of being a tough, but fair, prosecutor. Having numerous family members as teachers, Mr. Sedacca has a deep understanding and passion when representing clients in the teaching profession. He has represented clients from variety of backgrounds and he treats each case with the same level of preparation and diligence. The firm, now known as Neff & Sedacca, is proud to have him as its newest partner.

Rising Star SuperLawyers: 2015 - 2019

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