Here is the most accurate and up-to-date tissue depth data of contemporary adults you’re going to find anywhere. This data was gathered using CT scans of over 400 living adults. You can find the whole article in Forensic Science International, and I strongly encourage you to read it.
I wanted to put the information in a forensic-artist-friendly format, so I’ve created a high-res PDF chart for you to download. Feel free to use and share with your colleagues.
Here’s what you should know:
The FBI data includes the standard deviation information, which shows the minimum and maximum range for each point. This gives the artist a clear idea of how much they can deviate from “average” based on the skull structure.
The FBI pooled the ancestry and sex data (like Stephan’s tissue depth data) because there is actually very little difference in the thickness of tissue between between the races and sexes; it’s the differences in the skull structure that are key to facial approximation.
The FBI data shows how the population has grown, literally. For instance, the tissue depth at gonion for an average weight person today is the same as an obese person from Rhine’s 1980 table.
The FBI data was gathered with extremely accurate CT scans of almost 400 living adults, taken in the 2010-2013 time frame . Rhine’s table uses measurements from as little as three individuals, taken in 1980, by sticking needles into cadavers.
Have you ever wondered what those numbers in parentheses mean? That’s actually the number of people that were measured in each group. Clearly, data from 400 samples is better than 3 or even 37.
Here’s some tips on how to use the FBI tissue depth data:
Begin with the column that most accurately reflects the skull and information you have at hand. For instance, with an average skull, start with the average column. However, if there are robust features, maybe gonial flaring, then look to the right columns to see how you can adapt it. You don’t need to stick to one column. Likewise, for a rugged, skull believed to belong to a heavyset male, begin with the first column to the right of average, and go even heavier if you need to.
Remember, the skull is an organic, individual thing, it does not and will not “fit” into any one column all the time.
Lastly, and maybe most importantly:
This is why you, a forensic artist is creating the approximation. Anyone can stick to one set of numbers in a column, glue on markers, and connect the dots.
But that’s not what forensic artists are called in to do. We are supposed take the most current scientific data, and apply artistry to make it real, and human.