How to Hire a Private Investigator
A Step by Step Guide
Diesel Investigations
NYC’s Premier Boutique Private Detective Agency
Professional - Discreet - Knowledgable
NYC Based, Nationwide Reach
How to Hire a Private Investigator
Advice from a Former FBI Investigator
Most people don’t hire a private investigator until they are dealing with a problem they can’t solve on their own.
Maybe you’re an attorney preparing for trial and need a witness located or interviewed. Maybe you’re conducting due diligence on a business partner. Perhaps you’re facing a family, financial, or legal issue and need reliable information before making an important decision.
Whatever the reason, hiring the right private investigator matters.
After nearly 27 years as an FBI Special Agent, I learned that successful investigations rarely depend on luck. They depend on experience, judgment, persistence, and the ability to separate facts from assumptions. Those same principles apply when selecting a private investigator.
The first thing I recommend is identifying exactly what you need. Private investigators perform a wide range of services, including witness location and interviews, litigation support, background investigations, due diligence inquiries, fraud investigations, asset searches, and surveillance. Not every investigator specializes in every area. Before hiring someone, make sure their experience aligns with the nature of your matter.
Next, verify that the investigator is properly licensed. In New York, private investigators must be licensed by the state. Licensing alone, however, should be viewed as the minimum standard—not the ultimate qualification. Clients should also look for professional credentials, continuing education, and relevant investigative experience.
Organizations such as the National Council of Investigation and Security Services, National Association of Legal Investigators, and ASIS International emphasize the importance of selecting investigators who maintain professional standards, pursue continuing education, and operate within established ethical guidelines.
Experience is where meaningful differences begin to emerge.
One of the questions I encourage prospective clients to ask is simple: “What kinds of investigations have you actually conducted?”
There is a significant difference between reading about investigations and conducting them. During my FBI career, I worked criminal, national security, counterterrorism, kidnapping, fugitive, and complex fraud investigations. I served in leadership roles, managed investigative teams, coordinated with prosecutors, interviewed witnesses, and pursued facts in environments ranging from New York City to Somalia, Saudi Arabia, Thailand, Kenya, and Cuba.
While every private-sector case is different, investigative fundamentals remain remarkably consistent. You gather information, assess credibility, identify gaps, test assumptions, and follow the evidence wherever it leads.
Another area that clients often overlook is interviewing.
Technology is valuable, but investigations are still largely about people. Witnesses forget details. Sources provide incomplete information. Individuals sometimes tell partial truths. A skilled interviewer can uncover critical facts that never appear in a database search.
My own investigative approach has always emphasized interviewing and fact development. As a Certified Forensic Interviewer (CFI), I understand that obtaining accurate information often depends on preparation, listening, and asking the right questions rather than simply asking more questions.
Communication is equally important.
A professional investigator should clearly explain the scope of work, anticipated costs, likely challenges, and expected deliverables. Be cautious of anyone who guarantees results. Ethical investigators cannot promise what facts will be uncovered. They can, however, promise a thorough, objective, and legally compliant investigation.
Clients should also understand that legitimate investigators operate within strict legal and ethical boundaries. A reputable investigator will not offer to hack accounts, illegally obtain protected records, impersonate law enforcement officers, or engage in unlawful surveillance. If someone proposes shortcuts that violate the law, that should be a warning sign.
Trust is another factor that should not be underestimated.
Many investigations involve sensitive legal, financial, reputational, or personal matters. You should feel comfortable that your investigator will handle information discreetly and professionally. In my experience, trust is earned through competence, honesty, and transparency—not promises.
At Diesel Investigations, those principles guide every assignment. I founded the company after retiring from the FBI because I believe clients deserve experienced, fact-driven investigative services delivered with integrity and discretion. Whether assisting attorneys with litigation support, locating and interviewing witnesses, conducting due diligence, or helping clients navigate complex situations, the objective remains the same: uncover the facts and provide actionable information.
If you are considering hiring a private investigator, take the time to evaluate credentials, experience, communication style, and professional reputation. The answers you receive during that process will often tell you as much about the investigator as the investigation itself.
The right investigator won’t tell you what you want to hear. The right investigator will help you discover the truth.
And when the facts matter, that’s what counts.
How to Hire a Private Investigator
A Step by Step Guide
Diesel Investigations
NYC’s Premier Boutique Private Detective Agency
LETS TALK!
Confidential 15-Minute Consultation - No Obligation
Let's discuss your case and determine the best path forward - quickly and discreetly.
Give me a call at 888-296-0660 or Click Below