By the Same Hand: How Forensic Science Links and Catches Serial Killers

By Mark Allen Mynhier

For more than thirty-four years, across the United States Air Force and the Los Angeles Police Department, Mark Allen Mynhier made photographs that other people had to trust. In this book he explains the part of serial murder that television always skips. Not why they kill. How they get caught.

When a search team entered a house in South Los Angeles in 2010, the murder weapon was sitting in plain view. What the killer had hidden, behind a false wall he built with his own hands, were nearly a thousand photographs of women. Mark Allen Mynhier was the lead photographer standing in that garage. The case was the Grim Sleeper, one of the most prolific serial murder investigations in American history, and it is the case this book is built around.

BY THE SAME HAND makes one clear argument. Serial offenders are identified and convicted through evidence and methodology, not through the psychology of why they kill. Two files land on the same desk. The only question that matters is whether they belong to the same hand.

Drawing on two decades inside the Los Angeles Police Department's Scientific Investigation Division, Mynhier lays out the four pillars investigators actually use to link crimes and tell pattern from coincidence. Then he tests that framework against the cases you think you already know.

Ted Bundy, and the real cost of mobility. BTK, and the signature he manufactured for an audience. Zodiac, and the difference between a message and evidence. Samuel Little, and the victims a broken system never bothered to count.

The killer teams that shatter the myth of the lone offender. And the Grim Sleeper, told from inside the investigation by one of the people who documented i

Along the way he dismantles the myths that keep real cases from being solved, from the evil genius to the lone hunter to the belief that the victims are always women.

This is not a book about monsters. It is a book about method, written by one of the people who did the quiet work that puts evidence in front of a jury. Sometimes that work convicts a guilty man. Sometimes, done honestly, it frees an innocent one.

If you have read the headlines, watched the documentaries, and still want to know how these cases are actually broken, this is the book that tells you.

• Format: Paperback
• Language: English
• ISBN: B0HDM3X1J2
• ISBN13: 9798994037782
• Release Date: September 2026
• Publisher: Broken Thread Publishing LLC
• Length: 206 Pages
• Weight: 0.62 lbs.
• Dimensions: 0.5" x 6.0" x 9.0"