A Forensic Analysis of the Patterson-Gimlin Film

The Iconic Frame 352 of the Patterson-Gimlin Film from 1967

In the summer of 2021, I had an idea that I thought would make for an interesting forensic analysis of the Patterson-Gimlin film from 1967. I shared this idea with the Expedition Bigfoot producers and, last night, June 12, 2022, the results finally aired in the United States. See Travel Channel’s Expedition Bigfoot, S3 E13, “A Massive Discovery.”

My idea was to laser scan the Patterson-Gimlin (PG) site and then overlay the data with the film footage. Back in the day we used to call this workflow perspective matching. The scan data is super accurate and 1:1 in terms of scale so you can make very accurate measurements from it. By properly overlaying the film onto the scan data determining a myriad of biomechanical and environmental measurements becomes possible. All I had to ask the production team was, “Suppose I could tell you how tall the creature is?” They were all in.

This isn’t a simple process. It requires an intimate familiarity with the PG site itself, good scan data, objects in both the film and the scan data that can be positively identified as the same objects, and software to overlay the film and the scan data correctly.

Rowdy Kelley at the PG site

Rowdy Kelley is a passionate PG site expert. He knows every tree, rock, and log on the site intimately. No simple task as the site has changed dramatically in 55 years. Rowdy’s book is here: https://www.amazon.com/BLUFF-CREEK-PROJECT-Patterson-Gimlin-Rediscovery-ebook/dp/B09P22SNDW

Dave McDonnell is the computer graphics expert with the Expedition Bigfoot team tasked with the perspective matching process.

Bryce and I at the PG site

On site cast member Bryce Johnson and I did the actual scanning with the Emesent Hovermap. What was a relatively bare sand bar 55 years ago, as seen in the PG film, is now dense, overgrown forest.

The tricky part was in the post processing of the scan data. I needed to remove the trees – but only enough of them so we could match trees in the scan to trees in the film. I did this with CloudCompare and Pix4Dsurvey. Then, with Rowdy’s help, over more than a few Zoom calls, we oriented Dave on to key items in the scan data that he could match with in the film.

The results? We know with absolute certainty how tall the creature, aka Patty, is. Pretty cool right?

Rowdy gets us oriented at the PG site
Raw scan data of the PG site with the treetops removed
PG site data (point cloud and contours) in Pix4Dsurvey

The data gained from this exercise will likely be celebrated by some and hated by others. It will validate some theories and invalidate others. Like it or not, it’s science and a proven forensic workflow.

For my part this has to be one of the more interesting forensic surveys I’ve been involved with. The PG film is the second most watched film in history – second only to the Zapruder film.

My passion is to make stories better using technology, and by being part of a team whose passion, skillsets, and dedication all line up perfectly.

When folks ask me what I do for a living I’ll refer them to this project as a shining example.

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