Dr. Tom Harper thought he had committed the perfect crime. He had shot his wife in a manner that should have left the bullet hard to find and identify. Then he had repeatedly stabbed her dead body with a kitchen knife, and after wiping off any fingerprints, dropped the knife in their backyard. Nearby, he made several impressions in the soft dirt with a sneaker that was two sizes larger than his shoe size. The house had been ransacked, and jewelry and some other item were missing. It looked like the perfect setting for a random house invasion scenario.
Establishing an Alibi
Dr. Harper, the director of a large dental clinic, then left his house through the back woods and picked up his car, which was on an isolated road about a half mile away. One of the advantages of living way out in the country was in having no neighbors close by to see things they shouldn't. Harper proceeded to his office and went into a 9:00 am meeting with his staff. While he was committing this crime, he periodically went to his laptop and typed an e-mail to several people to establish that he was in his office all the time. To bolster his alibi, he sent the e-mails to his office computer using remote desktop software, and then forwarded them to the recipients. There would be no trace of the e-mails coming from his house.
Alice Harper was a large woman who worked out regularly at the gym. Tom Harper knew that he would never be able to stab her without her fighting back and leaving signs of a struggle. His plan was to shoot her in the back at close range with a small caliber .22 pistol. His knowledge of anatomy allowed him to shoot her in a way that would penetrate the abdominal aorta and cause her to immediately bleed out into her abdomen. Once on the floor, he would stab her repeatedly with a kitchen knife. Hopefully, at autopsy, they would only look at the stab wounds and not look for a small gunshot wound in her back. To ensure this, he also stabbed her in the back several times, including through the gunshot wound area.
But this plan left a problem: the bullet. Surely the medical examiner would find the lead slug. He had looked into frangible .22 bullets, something like a CCI Quik-Shok, but they only fragmented into two or three pieces and the likelihood of one or more being found would be too great. This kind of bullet would also tear up some other organs, and he wanted this to be a clean shot into the aorta. When he stabbed her, he would be sure to hit the aorta first in the front, making it look like a knife wounds had ruptured it.
This problem plagued him until one day, as he was rebuilding a patient's broken tooth, he had a thought. What if he removed the bullet from the .22 shell and built up a bullet made of dental restorative composite, like Gradia or some other polymer material? If he made the material not too smooth on the surface, it would probably be overlooked as a bone fragment, and he could color the composite to match bone. On studying some literature, he found that by incorporating calcium phosphate gel into the composite when he made it, the bullet would be strong enough to penetrate the body, but then break into several pieces. Furthermore, if he stabbed her in the stomach, the hydrochloric stomach acid would leak out, and could dissolve the calcium gel, degrading the bullet fragment even further.
Harper was convinced his scheme was foolproof. He prepared several bullets, then shot them into watermelons out in the woods, adjusting the polymers till he got the effect he wanted. He picked a Thursday morning to shoot her, knowing that her best friend would come at around 10:30 am to pick her up to go shopping. His last task was to break the window in the back door at the kitchen, the point of entry for the robber.