Philadelphia, PA  •  Pittsburgh, PA  •  Roaring Spring, PA  •  Chicago, IL  •  St. Louis, MO


  • International testimony & travel experience
  • Court Qualified in both State and Federal Courts in the United States

Often referred to as “Handwriting Experts,” Lesnevich & Detwiler have decades of experience in the field of forensic document examination. Their practice has covered a whole spectrum of examinations specific to forensic document analysis including standard cases involving only a single questioned signature to highly complex, highly sensitive matters involving thousands of questioned signatures.


The story of Lesnevich & Detwiler began in 1981 when Gus Lesnevich opened his own private practice after many years of service in the US Military and both state and federal courts. Gus built a solid reputation for preparing comprehensive and precise laboratory reports as well as effective court room presentations. This led him to become a highly sought after private and government expert in numerous high profile cases.

Similarly, Khody Detwiler has made a name for himself as a forensic document examiner in both national and international matters and was brought into the practice to meet the growing demands for reliable analysis, meticulous reports, and high-quality court graphics.

Since our beginning, we have been and continue to be court qualified in State, Federal, and International Courts, and we are equipped to handle any issue involving the authenticity of documents, writings, and signatures in both criminal and civil matters, such as:

  • Anonymous letters
  • Wills and other testamentary documents
  • Medical records
  • Insurance policy forms
  • Deeds and mortgages
  • Checks and banking transaction documents
  • Threatening letters
  • Contracts and agreements


We have expanded our practice to be able to increase service in the Midwest, specifically, in Chicago, IL and Saint Louis, MO. While we are still based out of Roaring Spring, PA, we have the ability to travel anywhere quickly.

We can handle on-site examinations as necessary, but our state-of-the-art laboratory is fully equipped and enables us to efficiently and securely conduct any type of analyses.

Examples of some on-site equipment we utilize:

  • Video Spectral Equipment to conduct non-destructive infrared and ultraviolet examinations of inks, papers, and other materials
  • Electrostatic Detection Equipment that can visualize and develop indented writings (either visible or latent) appearing on the surface of documents

We also offer other specialized lighting and laboratory instrumentation including stereoscopic binocular microscopes to conduct any type of microscopic analysis that may be necessary.

Visit our Services page to learn more about all the various services and analysis we can provide.


Lesnevich & Detwiler has worked hard to build and maintain the reputation as one of the foremost authorities on non-destructive forensic document and handwriting examination. Our goal is to uphold that standing.

As technology and methods in forensic document examination develop, we will continue to adapt and expand our laboratory so our clients can continue making confident decisions about the nature of a written or digital document.

Regardless of how our field or our practice transforms, we will always serve our clients to the best of our ability and never compromise on producing and presenting high-quality, highly-effective court illustrations and graphics to assist judges, juries, and arbitration panels in understanding the basis of our findings.

We practice on the belief that education and application is not only essential in any expert retention, it is the cornerstone to a successful outcome.


Contact our office and let us know how we can help.