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Judge's Table

Litigation expert witness in the fields of Security and Law Enforcement

A security and law enforcement litigation Expert is a professional with specialized knowledge, skills, or expertise in a particular field who is called upon to provide testimony in a legal proceeding. Their role is to assist the court or jury in understanding complex technical or specialized issues relevant to the case at hand. Overall, litigation expert witnesses play a critical role in helping the court or jury understand complex issues, evaluating evidence, and reaching informed decisions in legal proceedings. Their testimony can have a significant impact on the outcome of a case, making it essential to choose qualified and credible experts with relevant expertise.

Case Review

Review records to screen potential cases for merit and identify case strengths and/or weaknesses. Provide verbal consultation to clients, unpack complex concepts, explore alternative case theories, assist in trial preparation, and develop technical questions to help clients better understand their case without providing a formal expert opinion or commitment to participate in deposition or trial testimony.

Expert Witness Retention and Litigation

Review records and materials, provide verbal consultation author-written opinions, and provide deposition and trial testimony if needed while being compensated by the attorney directly for your services.


Mark J. Lang, MCJ, the owner of Investigations HQ, LLC, has a career covering over 40 years of extensive law enforcement, security management, and private investigation experience. I am committed to delivering impeccable results and maintaining the highest ethical standards in every endeavor. Accomplished and detail-oriented certified professional with extensive experience overseeing all aspects of organizational security, team leadership, and strategy development and execution. Adept at managing public safety and physical security functions and reviewing management reporting systems for public safety data. I have demonstrated expertise in mitigating all types of operational risks and adhering to set standards within fast-paced environments. 


Board Certified Protection Professional ASIS- CPP and IAHSS - CHPA Certified Healthcare Protection Administrator. I am also a licensed private investigator. I retired as a Special Investigations Captain from the Orange County Sheriff's Office. I have experience in special operations, criminal intelligence, and special investigations. Former Security Executive and Manager for a large hospital organization with experience in all aspects of hospital and organizational security. Member of the Southern Police Institute Alumni Association, Florida Association of Licensed Investigators, ASIS, and IAHSS.

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