Episode 093: Joseph DiZinno – FBI Laboratory, Katrinak Murder Case

Retired agent Dr. Joseph Dizinno, DDS. served in the FBI for 22 years. Prior to joining the FBI, Dr. DiZinno, who received a Doctor of Dental Surgery Degree from The Ohio State University in Columbus, Ohio, owned and operated a family dental practice. He was initially assigned to the Washington Field Office where he investigated reactive crimes. After three years in the field, he was promoted and transferred to the FBI Laboratory where he began to specialize in the examination of hairs and fibers. Dr. DiZinno served as a critical investigative resource on many high-profile cases including dental and DNA identification at the Branch Davidian Cult fire, kidnappings, and major extortion cases.  In this episode of FBI Retired Case File Review, Dr. DiZinno reviews the functions of  FBI Laboratory and the investigation of the tragic murders of Joann Katrinak and her baby Alex where mitochondrial DNA analysis was first applied to forensic casework. He was part of the research team that developed and validated forensic mitochondrial DNA analysis capability which enabled the FBI to obtain a DNA profile from evidence containing small or degraded quantities of DNA from hair, bone, teeth, and bodily fluids. Dr. DiZinno ended his Bureau career as the Director of the FBI Laboratory where he led more than 550 FBI Laboratory personnel, providing forensic examinations, technical support, expert witness testimony, and training to federal, state, and local law enforcement agencies and responding to events all around the world. Currently, Dr, DiZinno is a faculty member at George Mason University in Fairfax, Virginia where he teaches forensic science to undergraduate and graduate level students in the Forensic Science Program.

Laboratory Director (Retired)

Joseph DiZinno

4/20/1986 – 2/1/2008










The following are links to FBI Website and YouTube features about the FBI Laboratory and news paper articles about the investigation and trial of the tragic murders of Joann Katrinak and baby Alex:

FBI Website – The FBI Laboratory

NatGeoTV (Video) – 8/17/2015:  Modern Marvels -Inside the FBI Crime Laboratory


The Morning Call – (Photo Gallery):  Patricia Rorrer and the murders of Joann and Alex Katrinak

People Crime (Video) – 3/2/2017:  ID Examines Controversial 1994 Case of Woman Convicted of Murdering Ex-Boyfriend’s Wife and Son

Dr. Joseph DiZinno was assigned to the FBI Laboratory for 19 of his 22 years in the FBI and was its Director at the time of his retirement. The FBI Lab is a state-of-the-art facility located in Quantico, Virginia.












Jerri Williams

View posts by Jerri Williams
Jerri Williams, a retired FBI agent, author and podcaster, attempts to relive her glory days by writing crime fiction and hosting FBI Retired Case File Review, a true crime podcast available for free subscription on Apple Podcast, Google Podcast, Spotify, and other popular podcast apps. Her nonfiction book FBI Myths and Misconceptions: A Manual for Armchair Detectives and her FBI corruption squad police procedurals featuring Special Agent Kari Wheeler are available wherever books are sold.

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