The forensic science of ballistics goes way deeper than being able to accurately identify weapons at a glance, or even by examining the bullet casings left behind at a crime scene. A fired weapon can leave gunpowder residue on a victim or perpetrator, which can be damning evidence during trial. The bullet trajectory can also be deciphered from studying shells and bullet holes around the crime — these clues are puzzle pieces which are constructed to discover what exactly happened. The corpse can’t talk, but the evidence can. Bullet holes without any casings left behind can also be a great clue, telling the expert which type of weapon was used. Forensic science involving ballistics also incorporates the study of other weapons, like bombs. Gun-wielding criminals are under the scrutinizing eye of the ballistics expert studying residue, hydrostatic shock, vaporific effect, trajectory, and even physics to solve the crime.

Terminal Ballistics

In forensic science, Terminal ballistics is one of the most-applied sciences regarding gun crimes, and studies the way a bullet acts when entering and/or exiting an object. Objects slow the bullet down, but may not always stop it. The forensic scientist at the scene of the crime can determine where the bullet came from, what slowed it down and where it ultimately came to a stop. This can be particularly useful when studying a so-called ‘accidental’ crime, or a situation in which one person was murdered and the survivor claims to have killed the victim in self-defense, by accident, or perhaps to just have been an innocent bystander while a third party wielded the gun. For example, a carpenter named Mr. Meatballs is present when his friend Warren gets shot in the head and killed on the spot. Mr. Meatballs claims that an armed gunman burst into the house while Warren and himself sat beside one another, enjoying a beer. When Warren claimed not to have any money for the burglar, the gunman shot him in the head, killing him, before fleeing. Mr. Meatballs has a shady story, partially because he’s a slovenly man devoid of all emotions. Forensic science can’t convict a man based on his attitude, however. Instead, it studies the Terminal ballistics of the crime, which shows that the bullet passed through the side of Warren’s head, through the other side, and ended up in the wall near the floor. The only problem is that the bullet would have passed through Mr. Meatballs’ body as well, if he had really been sitting beside Warren as he had claimed. It is clear that the bullet did not pass through a second body, and Mr. Meatballs has told a lie — at least about the side of Warren he had been sitting next to. This also involves the study of trajectory, or the path that the bullet takes.

Trajectory

Trajectory can also tell a story. A crime scene with multiple bullet holes can be studied closely, and the holes can be traced to figure out where the gun was fired from. Other marks in the room can give away areas upon which the bullets have ricocheted off of.

Gun Signature

When a gun fires a bullet, it usually leaves microscopic markings on the bullet which are unique to that particular gun alone. Our old friend Mr. Meatballs may have claimed that the gun used to kill his poor friend Warren was a mystery weapon wielded by the mystery gunman, but ballistics tell a different tale. When Mr. Meatballs is served with a warrant and his own handgun is confiscated, his weapon is tested by shooting bullets out of it and then studying the marks left on those bullets. The microscopic markings, or ‘signatures’ on both the test bullets and bullets from the crime match up exactly with one another and the interior of his weapon. There’s no argument against the bullet signature because it’s unique, like a snowflake. Only more evil. Mr. Meatballs is looking guiltier by the second. In fact, this evidence is enough to put him in jail for the rest of his life, even if his story hadn’t been ousted as a lie.

Gunshot Residue

A fired gun leaves gunpowder residue on the hand that fires it. It can also leave gunshot residue, along with a small burn, on the victim’s body if he or she is shot at point blank range. Fumbling Mr. Meatballs didn’t wash his hands after firing his weapon, so detectives would easily have been able to arrest the man with that evidence alone. Unfortunately, he wasn’t considered a subject until over a day later, at which point the evidence from his hand had disappeared. The upside is that there are already other mounds of evidence against him…plus the burn mark on the side of Warren’s head, which indicates that the man was shot at point blank range and not from across the room as Mr. Meatballs is trying to claim. Forensic science is clearly winning this battle.

Famous Cases

Mr. Meatballs confessed in favor of taking a plea deal after he heard all the evidence against him and felt really, really stupid. It turned out that Warren was having an affair with Mrs. Meatballs. Mr. Meatballs will never work in this town again.

In 1927, forensic science genius Calvin Goddard was mainly responsible for the conviction and eventual execution of Nicola Sacco and Bartolomeo Vanzetti, two anarchists who shot and killed two men during an armed robbery in 1920. The bullet casings found at the scene of the crime were compared with the culprit’s gun barrels using a new state-of-the-art microscope and were found to match.

Goddard was also a key player in solving the St. Valentine’s Day Massacre, in which seven mobsters were gunned down by Al Capone’s men in 1929. The criminals were dressed as police officers, but were also caught using microscopic bullet comparison.