About Us

William Losefsky

William is a Board-Certified Criminal Defense Investigator, Board Certified Forensic Death Investigator, Certified Master Investigator, and a Certified Anti-Terrorism Specialist who has accumulated the necessary and critical experience and expertise to ensure that your unique case is given the utmost investigation prowess to produce the best possible outcome with an investigative service. 

William has a life long passion of achieving excellence and continuously avails himself the cutting edge strategies and continued education in pursuit of excellence for his clients.

William holds a Bachelor of Science degree from Springfield College as well as a Master of Business degree from Columbia Southern University. He is a licensed private investigator in the State of New Hampshire (License# M-2023-5905) and is the current President for the New Hampshire League of Investigators.

Investigative Concepts, LLC was established in 2002 by Principle Member William Losefsky and was designed to support Attorney’s, businesses, corporations, and individuals with professional and in-depth investigative services in New Hampshire. 

William is a retired law enforcement professional with extensive major case management experience. William was also a police prosecutor in New Hampshire, which gives him a unique and critical perspective on the criminal justice realm as he has equal experience working on both defense and prosecution strategies using best practices. William was also the Director of Security for large healthcare systems, where he routinely investigated theft, workplace violence, assault, drug diversion, abuse, and other complex investigations. This unique dual sided experience skill set gives your investigation an advantage and sets us apart from our competition. Investigative Concepts, LLC, will ensure that we tenaciously pursue the facts and explore and uncover all elements of your case.

” First, eliminate the impossible, whatever is left, however improbable, must be the truth.”

-Sir Arthur Conan Doyle

“I hear much of people’s calling out to punish the guilty, but very few are concerned to clear the innocent.”

-Daniel Defoe

Training System

I provide professional training across a diverse range of subjects tailored to enhance investigative and security skills. My training programs include:

  1. Interviewing Techniques: Mastering the Art of Conducting Effective and Thorough Interviews.
  2. Handwriting Analysis: Applying forensic techniques to analyze handwriting for authenticity and psychological insights.
  3. Statement Analysis: Techniques to discern truthfulness and detect deception in written and verbal statements.
  4. Safety and Security Planning: Developing comprehensive plans to ensure organizational safety and mitigate security risks.
  5. Report Writing: Crafting clear, detailed, and professional reports for investigative and security purposes.
  6. Managing Large and Complex Criminal Cases: Strategies and Methodologies for Handling Multi-faceted Criminal Investigations.
  7. Criminalistics: Applying scientific principles and techniques in crime scene investigation and evidence analysis.
  8. Courtroom Testimony Preparation and Guidelines: Preparing witnesses and investigators for effective and credible courtroom testimony.
  9. Workplace Violence / Active Shooter techniques and tactics.
  10. Project Management for the Security / Investigator Practitioner.

These training sessions are designed to equip professionals with the essential skills and knowledge to excel in their respective fields, ensuring thorough preparedness and proficiency in their roles.

William has presented to many large organizations and agencies. Some of our presentations were to:

1. State of New Hampshire Corrections Department
2. Vermont Attorney General’s office
3. NH Corrections Department
4. Belknap County Sheriff’s Department
5. National Association of Drug Diversion Investigators
6. International Association of Healthcare Safety and Security
7. Penn State Health
8. Mountain States Health Alliance

Investigative Concepts, LLC

Investigative Concepts, LLC, can provide significant assistance to an attorney in a variety of ways, leveraging their skills, resources, and expertise to support legal cases. Here are several key ways a PI can assist an attorney:

  1. Gathering Evidence

    We are skilled in collecting various types of evidence, including:
    • Surveillance: Conducting discreet observation of individuals to gather information about their activities.
    Interviews and Statements: Taking statements from witnesses, victims, or other parties involved in a case.
    Background Checks: Investigating the background of individuals to uncover past criminal records, employment history, financial status, and more.
    Document Retrieval: Locating and obtaining important documents such as public records, court files, or corporate records.

  2. Locating Individuals

    • Witnesses: Finding and interviewing witnesses who can provide crucial testimony.
    Missing Persons: Tracing and locating missing persons, including runaways, debtors, or individuals who have fled to avoid legal proceedings.
    Defendants: Locating defendants who are evading service of process.

  3.  Case Analysis and Research

    Fact-Checking: Verifying facts and details provided in legal cases to ensure accuracy.
    Investigative Research: Conducting in-depth research on complex matters involving multiple sources of information.
    Expert Analysis: Providing expert analysis on specialized topics such as fraud, cybercrime, or forensic accounting.

  4. Litigation Support

    Trial Preparation: Assisting in the preparation of cases for trial by organizing evidence, preparing exhibits, and creating timelines.
    Witness Preparation: Helping attorneys prepare witnesses for deposition or trial by familiarizing them with the process and potential questions.
    • Jury Selection: Assisting in the jury selection process by conducting background checks on potential jurors.

  5. Fraud and Financial Investigations

    Fraud Detection: Identifying and investigating instances of fraud, embezzlement, or financial misrepresentation.
    Asset Searches: Conducting searches to locate hidden assets, which is particularly useful in cases involving divorce, bankruptcy, or debt collection.

  6. Corporate Investigations

    Internal Investigations: Assisting with investigations into corporate misconduct, employee theft, or violations of company policy.
    Due Diligence: Conducting due diligence investigations for mergers, acquisitions, or other business transactions to ensure all relevant information is uncovered.

  7. Digital and Cyber Investigations

    Cybercrime Investigation: Investigating cybercrimes such as hacking, identity theft, or online harassment.
    Digital Forensics: Recovering and analyzing data from electronic devices to find evidence relevant to legal cases.

  8. Personal Injury and Accident Investigations

    Accident Reconstruction: Reconstructing accident scenes to determine the cause and identify responsible parties.
    Insurance Claims: Investigating the validity of insurance claims to prevent fraud and ensure rightful compensation.

  9. Family Law and Custody Cases

    Custody Investigations: Gathering evidence in child custody disputes to determine the best interests of the child.
    Infidelity Investigations: Providing evidence in cases of suspected infidelity, which may impact divorce settlements.

  10. Criminal Defense

    Exoneration Evidence: Finding evidence that may exonerate a defendant or reduce charges.
    Witness Cross-Examination: Uncovering information that can be used to challenge the credibility of prosecution witnesses.


Investigative Concepts, LLC, brings a wealth of knowledge, resources, and investigative skills to support attorneys in building stronger cases, uncovering crucial evidence, and achieving favorable outcomes for their clients. Our ability to work discreetly and effectively makes us invaluable partners in the legal process.

Professional Certifications & Licenses

Board Certified Criminal Defense Investigator
Certified Master Investigator
Board Certified Forensic Death Investigator
Certified Healthcare Protection Administrator (CHPA), IAHSS
Safety Certificate Program, State of New Hampshire
Certified Anti-Terrorism Specialist (CAS), ATAB
Crime Prevention through Environmental Design (CPTED)
Certified Identity Risk Manager (CIRM)
Certified Public Manager (CPM) and Certified Public Supervisor (CPS), State of New Hampshire
Certificate in Supervision & Management, University of New Hampshire
Certificate in Industrial Hygiene, Columbia Southern University
Certificate in Occupational Safety & Health Standards, U.S. Department of Labor