A twenty-year old man was found supine on Thompson Creak (haha I think you meant 'creek') Trail with a bullet wound. The entrance of the wound was on the left lateral side 1 cm above the third rib. The exit wound was 5 cm above the belly button in the umbilical region. While tracing the bullet path you notice at the entrance the bullet travels in the frontal plane with a 45-degree downward angle. On inspection of the right side of the rib cage by x-ray, you observe the 8th rib fractured. Fragments of bullets are then traced to the final exit wound. What is the leading differential diagnosis (and why) and what are three plausible alternatives and how would you rule them out?

This man, we will simply call John Doe, was presumably shot from the back presumably because the exit wound was 5 cm above the belly button in the umbilical region (which means he could not have been shot from the front).

Mr. Doe was also found supine and not prone, which is indeed a big problem for the wound ballistic department because this meant that he did not die immediately. If Mr. Doe was shot on the back--close proximity or not-- and died immediately, he would have fallen forward from the force of impact, putting him in the prone position. However, Mr. Doe was found in the supine position, which leads us to several possibly situations. One, Mr. Doe managed to turn around and look at his murderer after he was shot, before he fell backwards. Two, Mr. Doe managed to roll himself around after being shot Nonetheless, this shows us that the bullet was not the immediate cause of Mr. Doe's death. 

The fact that Mr. Doe had bullet fragments in his body means that he was shot with a jacketed bullet, because jacketed bullets are designed to fragment after impact in order to divide their destructive power. However, there is a very likely possibility that Mr. Doe did not die from impact of the bullet, but rather from the exit wound that was caused by the shot-- Mr. Doe could have bled to death. When a bullet enters the body, it causes lacerations and crushing wounds. It also punctures through tissue and bone, crushing or pushing aside anything in its path. When a bullet passes through tissue, it creates a cavity that can be thirty times wider than the path it takes, the track. Although this cavity closes behind the bullet less than a second after the bullet passes, the cavitation it causes can damage nearby tissue, organs and bones via shock wave. Exit wounds tend to be larger than the entrance wound because as the bullet moves through the body, it slows down and explodes within the tissue and surrounding muscle. This slowing down of the projectile means that as it reaches the end of its trajectory, it has to force harder to push through. This causes the exit wound to look larger and therefore more destructive than the entrance wound. Exit wounds often bleed profusely as they are larger, whereas entrance wounds can sometimes look only like small holes--unless the weapon was fired as close proximity to the victim.

Considering that the bullet was shot at a 45 degree angle, I would have to guess that the shooter was located at a higher angle or plane. This is because the shooter would have to be extremely tall in comparison to the victim for the victim to get shot at a 45 angle, even though they were on the same ground level.

Leading Differential Diagnosis: Mr. Doe was shot from behind, at a higher ground level, and died from blood loss caused by the bullet wound. Mr. Doe, however, managed to roll himself over (a natural human instinct, at least it seems) before he died.
Problem: Lack of evidence: there was no mention of pools of blood surrounding the body, or mentions of dirt particles on the front of his shirt, which would have suggested that he rolled himself into the supine position.

Alternative 1: Mr. Doe was poisoned then shot by the murderer to cover up the true cause of death. Mr. Doe was then transported to the crime scene for a nearby jogger to discover.
Problems: Lack of evidence, including missing toxicology report and no mention of pools of blood surrounding the body.

Alternative 2: Mr. Doe died immediately after he was shot, but the crime scene was contaminated by the discoverer of the corpse who must have turned over the body to inspect if he was still alive.
Problems: The bullet could not have punctured the heart, causing immediate death, if it fractured the eighth rib and exited through the umbilical region at a 45 degree angle. There is also lack of evidence saying that the discoverer contaminated the crime scene.

Alternative 3: Mr. Doe was jogging uphill, when the shooter (at a higher ground level, say camping on a tree) shot him from above. Shocked, Mr. Doe fell backward into the supine position (ouch). He died immediately.
Problems: This one is the least likeliest to happen because he would have fallen forward from the impact of the bullet no matter how steep the hill was. Even if he did fall backward because of some weird situation (you never really know), it still doesn't explain why there are hills on Thompson Creek Trail (I've been there and there are none!! I tihnk... I jogged like 2 miles so I really don't have much of a say on this..). There is also lack of evidence on the surroundings to conclude with this alternative.

Rachel Putri Utomo
Block F, Honors Biology
Mr. Kevin Quick
Academic Year 2013-2014