Catching a Killer- 7 Tremendous Advances in Forensic Science
Catching a Killer- 7 Tremendous Advances in Forensic Science

Catching a Killer- 7 Tremendous Advances in Forensic Science

Michelle Powell-Smith - October 9, 2016

Catching a Killer- 7 Tremendous Advances in Forensic Science

DNA, 1987/2001

In the 1980s and 1990s, bodies began appearing along the Green River in Washington state. Most of the bodies were found in wooded areas. All of the victims were female, and those that could be identified were prostitutes or runaways. At least 71 murders have been linked to the Green River killer. By the early 1980s, the local sheriff’s department had formed the Green River Task Force to investigate the murders.

In 1983, Gary Ridgway was questioned as a suspect in the murders. He remained a suspect for a number of years, but was not taken into custody. He took a polygraph test in 1984, and was deemed to have passed, although this result has been called into question since the time of the test. In 1987, police collected saliva and hair samples from Ridgway.

The samples taken in 1987 were key to Ridgway’s 2001 arrest. In 1987, the technology to match DNA did not exist. DNA specialists were able to match Ridgway’s DNA to semen found in the bodies of four of the victims. Additional charges were brought for three additional victims, connected by spray paint samples matched to Ridgway’s workplace.

In 2003, Ridgway pled guilty to 48 charges of aggravated first degree murder. The plea bargain contained the names of 41 additional victims. He was sentenced to 48 consecutive life sentences, with no possibility of parole; the plea bargain took the death penalty off the table for Ridgway.

When police swabbed for saliva and took hair samples in 1987, the DNA technology that led to Ridgway’s arrest was still far in the future. Blood type matching was possible, but there was no way to decisively identify an individual by DNA. Their foresight led to his eventual conviction.

Catching a Killer- 7 Tremendous Advances in Forensic Science

Forensic Computer Analysis, 1974-1991/2004

Between 1974 and 1991, ten people in the Wichita, Kansas area were found killed. All of the victims had been bound, tortured and killed. In January 1975, four members of a family were killed. Six additional female victims were killed over the next 15 years.

The killer, then unidentified, began to communicate with the police through a series of notes. In the first of these, he named himself BTK for bind, torture, kill. He continued to send notes, frequently including puzzles, poems and pictures, to the authorities, either directly or through the media for a number of years. The communication stopped in 1994.

In 2004, after a decade of silence, communication between the police and BTK resumed. BTK sent police a floppy disk, with a document created in Microsoft Office. This was, at long last, BTK’s error. Through forensic analysis, they found that the document was created by someone named Dennis at Christ Lutheran Church in Wichita. They found that Dennis Rader was a congressional leader at Christ Lutheran Church. DNA evidence further linked him to the case.

Dennis Rader, BTK, made his first great error as a serial killer when he opted to go high-tech. While police had been unable to catch him using physical evidence at crime scenes, or the many notes and communications with the police, he was caught quickly after forensic analysis of a single floppy disk.

Rader initially pled not guilty to the murders. He eventually confessed and is in prison for his crimes. He will die in prison, with no potential for parole during his lifetime.

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