Cross posted from Frederick Leatherman Law Blog.

Trayvon Martin's parents speak at a crowded rally.

Trayvon Martin's Parents at a rally for justice (Photo: David Shankbone / Flickr).

Amy L. Siewert is a Crime Laboratory Analyst employed by the Florida Department of Law Enforcement Crime Laboratory. She examined TM’s Fruit of the Loom dark gray hooded sweatshirt (Exhibit ME 12) and the light gray Nike sweatshirt (Exhibit ME 8) that he was wearing underneath the hoodie when GZ shot and killed him

In her report dated March 22, 2012, she concluded:

The sweatshirts each display a hole located in the upper chest area. The areas around these holes were microscopically examined and chemically processed for the presence of gunshot residues. Both holes displayed residues and physical effects consistent with a contact shot.

In her bench notes, which the prosecution released in the recent document dump last Thursday, she specifically noted that her microscopic examination of the the light gray sweatshirt (ME 8) “shows results consistent with a contact shot (tearing a hole, sooting around the hole, burning/singeing, no powder pattern, vaporous Pb surrounding the hole). She also noted that the hole exhibited “stellate” tearing. She described the hole in the hooded sweatshirt (ME 12) identically, but noted L-shaped tearing.

These are the classic signs of a contact shot. That is, the muzzle of the gun was in contact with the outer hooded sweatshirt with the light gray sweatshirt immediately behind, or in contact with it.

She also test fired GZ’s gun into squares of cloth cut from both sweatshirts and verified that the muzzle of the gun was in contact with the sweatshirts.

She also noted that the holes in the sweatshirts align with each other.

She also measured the vertical distance from the hole up to to the neck seam at approximately 7 inches. The horizontal distance to the shoulder seam was approximately 7 1/2 inches.

Although these holes align with each other, they do not align with the entry wound in TM’s chest. According to the autopsy report, the entry wound is 1 inch left of the midline and 1/2 inch below the left nipple.

Therefore, the entry wound is approximately 3 1/2 inches below and 2 1/2 inches closer to the midline than the holes in the sweatshirts.

Also significant is that the entry wound was caused by a gunshot in which the muzzle of the gun was at an intermediate range of 2-4 inches.

What does this mean?

I believe it means the sweatshirts were being pulled down or being held by GZ as TM was pulling back or attempting to stand up (and probably screaming for help as he did so) when GZ pressed the muzzle of his gun against the hooded sweatshirt and pulled the trigger. The two sweatshirts were in contact with each other (i.e., gripped together) and approximately 2-4 inches from his chest.

The trajectory of the shot would have been straight through neither varying up or down nor left or right, if TM were leaning forward while attempting to get away, but restrained from escaping by GZ’s grip on his sweatshirts.