11Green River killer
Green River killer would cover his tracks by buying new car tires and destroying shoes and getting new ones after murders (to avoid leaving traceable tracks behind). He took the jewelry off his victims and left it in the ladies restroom at his workplace and got off on seeing the “found” jewelry on the various women around the office.
12Dr. Harold Shipman
When Dr. Harold Shipman lost his mother, he saw how morphine eased her pain before she passed. Then he became a doctor and used morphine overdoses to kill people, especially rich old ladies, and wrote himself into their wills with forgery. He was eventually caught because it was suspicious that every single one of his patients had him in their will, and that they all died under his care - but he did “inherit” a number of estates and a lot of money before getting caught.
A Polish serial killer named Paweł Tuchlin was admitted into a psychiatric ward. He started making sculptures out of bread and was quite good at it. He fell in love with one of the doctors there and to show his affection he made a vagina out of bread (he used natural hair too) and then gave it to the doctor. She then suffered a mental breakdown.
Israel Keyes used to fly to one state and then rent a car and drive thousands of miles to kill someone. He never stalked his victims, he would pick at random and connivance. He only got caught because he kidnapped a girl and held her for ransom and started taking money out of her account. It was the first time he ever did that. If he would have just kept doing what he was doing he would have never been caught.
Dennis Rader, a Kansas serial killer, a.k.a. the BTK Killer, installed alarms as a part of his job, and many of his clients had booked the company to stop BTK from ever entering their homes, unaware that BTK himself was installing them. He was finally caught after sending a 1.44MB diskette to the police - which they told him was untraceable - containing metadata from a deleted MS Word file.
David Berkowitz (aka the Son Of Sam) killed people because he believed that he was commanded to do so by a demon that resided in the body of his neighbor’s dog, Harvey.
John List lost his job at a bank and was so scared of losing his home and bringing shame and distress to his family that he meticulously planned the murder of his wife, mother, and kids so that weeks went by before anyone realized they were missing. He then left the bodies in sleeping bags in the ballroom of the family’s mansion, cut his face out of all the family photos, and moved away to start a new life and eventually found a new wife. He was caught almost two decades later when an age progression clay bust was made of his face and shown on America’s Most Wanted.
Andrei Chikatilo was a Russian serial killer who targeted children and was said to have used parts of their anatomy as chewing gum while he walked the streets. The Soviet state was adamant that serial killers were a product of western moral failings and that the crimes were not related. Many of his victims were pinned on other men including his first murder even though a great deal of evidence pointed in his direction at the time. Andrei's job was to travel between factories delivering parts which let him spread out murders in different jurisdictions which of course was hampered by a lack of communication between police services. He was at one point arrested for acting suspiciously in public and found to have knives, rope, and Vaseline in his possession but this did not lead to him being charged with any murders.
Richard Ramirez, AKA “The Night Stalker”, who killed 13 people in the 80s once tried escaping from prison and had shoved multiple things, including an “I Luv Chocolate” Sticker, up to his ass for supplies.
Hadden Clark, a serial killer and cannibal currently serving life in prison has a brother, Bradfield Clark, that he was estranged from for most of his life. As it would turn out not only did his brother murder his girlfriend, but he roasted chunks of her breasts on a BBQ and ate them.