About John Halverson
John Halverson is a seasoned criminal defense trial attorney representing clients in high-stakes and high-exposure criminal matters throughout Suffolk County and the New York metropolitan area. With decades of courtroom experience, he is widely recognized for his strategic judgment, disciplined advocacy, and steady presence in complex and serious cases.
Mr. Halverson handles significant criminal matters including felony charges, manslaughter and homicide-related prosecutions, assault allegations, abuse-related cases, DWI and DUI offenses, and major narcotics investigations. He is frequently retained in situations where personal freedom, professional reputation, and long-term future are at risk.
He began his legal career as a Senior Assistant District Attorney in the Suffolk County District Attorney’s Office, where he prosecuted major violent felony cases and developed extensive trial experience. This background provides him with a sophisticated understanding of prosecutorial strategy and courtroom dynamics — insight he now applies in crafting focused, strategic defenses.
Over the course of his career, Mr. Halverson has earned a respected reputation and longstanding professional relationships within the Suffolk County legal community. His credibility among prosecutors, fellow defense counsel, and members of the judiciary — combined with his deep familiarity with local court practices — allows him to navigate complex matters with discretion, confidence, and precision.
He previously practiced within a well-established Suffolk County law firm serving multiple legal disciplines, where he focused exclusively on criminal defense and trial work. He now represents clients from his office in Central Islip on Carleton Avenue, continuing to defend individuals in serious state and federal criminal proceedings.
A lifelong Suffolk County resident, Mr. Halverson remains deeply connected to the community he serves. He is married to executive coach, consultant and certified hypnotherapist Melissa Ann Halverson, and together they have raised their triplet daughters on Long Island.
Experienced Defense Counsel — When It Matters Most
Approach
Strategic Defense. Trusted Courtroom Presence.
Criminal allegations can place every aspect of a person’s life at risk — personal freedom, professional standing, financial stability, and family security. John Halverson approaches each case with disciplined preparation, strategic judgment, and a clear focus on protecting his clients’ long-term interests.
Drawing on decades of experience in both prosecution and defense, he evaluates cases with precision, anticipates prosecutorial strategy, and develops thoughtful trial and negotiation approaches designed to achieve the strongest possible outcomes.
His representation is defined by discretion, responsiveness, and steady leadership during highly stressful and uncertain situations.
Representative Matters
Mr. Halverson has represented clients in a wide range of serious and complex criminal matters, including:
Violent felony and homicide-related prosecutions
Manslaughter and major assault allegations
Domestic and abuse-related criminal charges
Driving while intoxicated (DWI) and DUI offenses
Significant narcotics investigations and prosecutions
High-exposure matters involving professionals, business owners, and community leaders
Each matter is handled with careful attention to legal strategy, reputational considerations, and the broader impact on a client’s future.
Why Clients Retain John Halverson
Decades of serious felony trial experience
Former Senior Assistant District Attorney, Suffolk County
Established credibility and professional relationships within the local courts
Strategic and discreet handling of sensitive legal matters
Direct attorney involvement and personalized representation
Calm, authoritative advocacy when outcomes matter most
Deep Roots in the Suffolk County Legal Community
As a lifelong Suffolk County resident, Mr. Halverson brings a strong understanding of the local legal landscape and court system. His longstanding reputation among judges, prosecutors, and fellow defense attorneys enhances his ability to navigate complex cases with confidence and clarity.
Confidential Consultation
Individuals facing criminal investigation or charges are encouraged to seek experienced legal counsel as early as possible.
To discuss a matter privately, contact the office to arrange a confidential consultation.