Use of Force | Law Enforcement Operations | Florida & Nationwide | Retired OCSO Captain

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Cases involving law enforcement conduct require an expert who has lived and led within the profession. Whether the issue is a use-of-force incident, a failure to follow established procedures, a wrongful arrest, or systemic failures in department policy, the credibility of the expert witness depends on firsthand command-level experience.

Mark J. Lang, MCJ, CPP, CHPA, brings exactly that. As a retired Captain of the Orange County Sheriff's Office Special Investigations Division — one of Florida's largest sheriff's agencies — Mr. Lang supervised complex investigations, implemented policy, and operated at the executive level of law enforcement for decades. He now applies that expertise as an independent expert witness in civil and criminal matters involving police conduct.

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Areas of Expertise in Law Enforcement Cases

Mr. Lang evaluates law enforcement conduct against the standards, policies, and procedures that govern professional policing. His areas of expertise include:

• Use of force — reasonableness, proportionality, and departmental policy compliance

• Deadly force — Graham v. Connor standards, threat assessment, and officer decision-making

• Arrest procedures — probable cause, detainee handling, and civil rights

• Investigative standards — criminal investigation protocols, evidence handling, and chain of custody

• Supervisory liability — command responsibility, policy failures, and deliberate indifference

• Training and policy adequacy — whether departmental training and written policies met professional standards

• Correctional and detention practices — inmate supervision and safety protocols
   

The Graham v. Connor Standard

In use of force cases, the controlling federal framework is Graham v. Connor (1989), which requires courts to evaluate whether force was objectively reasonable from the perspective of a reasonable officer on the scene, given the totality of the circumstances. Mr. Lang analyzes the facts of each case within this framework, accounting for the severity of the alleged crime, whether the subject posed an immediate threat, and whether the subject was actively resisting.

He also evaluates compliance with department-specific use of force policies, state statutes governing law enforcement conduct, and accepted national standards such as those promulgated by CALEA (Commission on Accreditation for Law Enforcement Agencies).
 

Law Enforcement Expert Witness Qualifications

Mark Lang's qualifications to serve as a law enforcement expert witness are grounded in direct, senior-level operational experience:

• Retired Captain, Special Investigations Division, Orange County Sheriff's Office — one of Florida's largest agencies

• Decades of supervisory and command-level law enforcement experience

• Graduate of the prestigious Southern Police Institute — Command Officers Development Course

• Master of Criminal Justice, Boston University

• Active member, Southern Police Institute Alumni Association

• Experience developing and evaluating law enforcement policy and training programs
   

Mr. Lang has testified and consulted in civil rights litigation, excessive force claims, wrongful death actions, and matters involving alleged failures in law enforcement policy and supervision.
 

Case Types Handled

• Excessive force and police brutality claims

• Wrongful death actions involving law enforcement conduct

• Section 1983 civil rights claims against officers and agencies

• Failure to train and failure to supervise claims

• Wrongful arrest and unlawful detention

• Police pursuit and vehicle operation cases

• Inadequate investigation claims

• Jail and detention facility misconduct
   

Serving Attorneys in Florida and Across the United States

Mr. Lang is available to serve as an expert witness or consultant for plaintiff and defense attorneys in Florida and nationwide. He is located in the Orlando metro area and is licensed as a Florida Private Investigator (License #A170078), which supports investigative support in conjunction with expert witness engagements.