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Former Federal Agent, Forensic Expert, & Private Investigator


Mark Gillespie specializes in criminal defense investigations, cold cases, human trafficking, and missing persons.

He is the owner of Gillespie Forensics & Investigations which was founded in 2004 predating this is a very impressive professional history.


Over the span of his career Mark has worked with the Air Force as a special agent and also was the Director of Forensic Science for Austin Police Department. He held a position as a professor of forensic science and criminal justice for St. Edwards University (SEU) in Austin, Texas. These are just a few of the accomplishments he has made over the years.

Mark is currently involved in the research and investigation of the Guy Heinze Jr case and is working closely with Jake Brydon, to investigate the case thoroughly.


Mark has a passion for seeking justice for victims and the accused.

He also documents his work on youtube and uploads updates on public cases he is working on along with topic based videos. The links to his social media can be found below.


Mark has served as a forensic and investigative expert on many true crime podcasts, including 2 from the Top 10 Best True Crime Podcasts of 2020, “Culpable” and “Without Warning”.


He as also appeared on the Investigation Discovery (ID Network) as well as FoxNews.









Below is a video from Marks Youtube regarding the Alicia Adams' case. 

He gives a full breakdown of the timeline of this case along with other specifics. This video gives you a good idea of what Mark does and what his role is as an independent investigator.

** Please note this video talks about the abuse of a child, some people may find this emotionally disturbing.

If any of the topic affects you and you feel like you need support with this you should seek help immediately.

You can contact your GP or emergency NHS mental health services in your area, or speak anonymously to a helpline like the Samaritans, who are open 24 hours a day on 116 123 (UK).

For those in the USA call 1-800-985-5990 or text “TalkWithUs” to 66746 at the SAMHSA Disaster Distress Helpline. Trained crisis workers will listen to you and direct you to the resources you need. **

This page is updated regularly there will be more information added on subjects including: - 

 The Investigation, The Case according to Law Enforcement, a breakdown of the news coverage, The Trial, The Evidence, Who was on the Case and where are they now, Guys conviction and current situation, who are Eye on Innocence, The life on Death Row BBC Documentary.

Any information on this page has been verified by Guys family, partner and/or official documentation.

© 2020 -

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