Crime

Catching a Killer- 7 Tremendous Advances in Forensic Science

Michelle Powell-Smith - October 9, 2016

Forensic science has changed how crimes are solved, and made it much harder to get away with murder. Scientific analysis of criminals and the scientific identification of culprits functionally began in the late 19^th century; this marks the beginning of effective police work. As technology and science has advanced, new fields of forensic science have opened up, including DNA and computer forensic analysis.

Fingerprinting, 1892/1892

In 1892, a woman named Francesca Rojas claimed to have found her two children, a six-year-old boy and four-year-old girl, dead in her home in Necochea, Argentina. Rojas blamed a rejected suitor, Velasquez, claiming that she had seen him fleeing her home.

Velasquez was arrested and tortured, but maintained his innocence throughout the torture, even after being tied to the bodies of the two children overnight. Since he did not confess to the crime, eventually, the police began to look elsewhere to find the killer.

An anthropologist and investigator in the regional Argentinian police office, Juan Vucetich, had an interest in criminal identification, and had heard of the new developments in fingerprinting. He was already using Bertillon’s techniques, a system of eleven measurements used to identify criminals. He sent a man to review the evidence at the crime scene. The investigator found a bloody fingerprint on the door of Rojas’ home.

Police took an ink fingerprint from Rojas and compared her fingerprint to that recorded from the scene of the crime. The two prints were matched, and Rojas confessed to killing her children. She had hoped to eliminate her children to get her boyfriend, who was uninterested in the children, to marry her.

Fingerprinting technology is commonplace today, but was very new technology in 1892. It would be a number of years before fingerprint technology found a home in Britain or the United States. In Argentina, Juan Vucetich went on to begin the first database of fingerprints and introduced the widespread use of fingerprint identification in Argentina.

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Handwriting Analysis, 1932/1936

The Lindbergh baby kidnapping and murder was national news within only hours of the baby’s disappearance in 1932. The 20-month old’s body was found six weeks after his death, and an autopsy showed that he had died of head trauma the very night he was taken from his home. The child’s death was possibly accidental; however, he died in the course of the kidnapping.

The search for the kidnapper took significantly longer. There was relatively little evidence, but the kidnapper had left a ransom note, and the family had paid a ransom before the child’s body was discovered. In total, there were 15 ransom notes from the kidnapper to the family. The ransom note, and the paid ransom, was key to the eventual trial and conviction of Bruno Richard Hauptmann. Hauptmann was found after investigators tracked the serial numbers on the ransom payment.

Eight document examiners took the stand in the trial, testifying that Hauptmann’s handwriting matched that of all of the ransom notes, including the one left on the night of the kidnapping. The handwriting experts relied upon the shape of letters, angle of the letters, and spelling patterns present in the ransom notes, requested writings by Hauptmann, and writings attributed to him, like official documents.

Hauptmann was convicted of the kidnapping and murder of the Lindbergh baby and put to death in the electric chair in April 1936. The handwriting analysis played a key part in his conviction; however, it was not the only evidence in the case. Even today, there are questions about the validity of the conviction, with some scholars believing evidence was manufactured, and others believing that the case had ample evidence, and was clearly proven.

Today, handwriting analysis continues to play a role in criminal investigations, and the FBI maintains a Questioned Documents Unit that analyzes documents in federal criminal cases. Their investigations include handwriting analysis, as well as study of paper, ink and other forms of forensic evidence.

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Wound Pattern Analysis, 1970/1979

On February 17, 1970, Jeffrey MacDonald phoned the police to report a stabbing. When police arrived, they found that MacDonald’s wife, Collette, and his two daughters, had been murdered. Collette, pregnant with her third child, had been clubbed and stabbed with two different weapons. Five-year-old Kimberly had been clubbed and stabbed, and two-year-old had been stabbed multiple times. MacDonald’s torn pajama shirt was laying on top of his wife’s body, and he was found with a number of relatively shallow stab wounds and a mild concussion.

MacDonald claimed that four individuals had entered his home and that he had awoken to his wife and daughter’s screams. He said he was attacked and left unconscious before the intruders killed his wife and children. Investigators were immediately suspicious. The evidence did not match up with MacDonald’s story. Fibers from the shirt he claimed to have had on were found under the bodies of his wife and daughter, and all of the weapons, as well the fingertip of a rubber glove, were found in the home.

MacDonald was charged in a military hearing, an Article 32 Hearing, in May 1970. Investigators hypothesized a very different scenario than the one described by MacDonald. They believed that a fight had begun between Jeffrey MacDonald and his wife, leading to her initial injuries. The older child may have been injured in the struggle. MacDonald went on to complete the murders, trying to stage a scene reminiscent of the crimes associated with Charles Manson. Nonetheless, the hearing concluded that MacDonald was not responsible. MacDonald was finally arrested after a continuing Justice Department investigation in 1975.

On the witness stand, an FBI technician showed the court how the torn and damaged pajama shirt had been damaged. In fact, when folded, the ice pick holes in the shirt perfectly matched the wounds on Collette MacDonald’s body. In addition, they showed that MacDonald’s story about the pajama shirt, in which he claimed to have wrapped it around his arms to defend himself, could not be true.

Today, wound pattern analysis, along with blood spatter and other forms of pattern analysis, is essential to the forensic investigation of crimes, including murder.

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Bite Mark Matching, 1978/1979

In January 1978, two young women were murdered by serial killer Ted Bundy. Both had been strangled and beaten. One of the two, Lisa Levy, had been raped and bitten several times. There was relatively little evidence left at the scene; however, photos were taken of the bite marks. Bite mark evidence was not new, but this case was one of the most important decided by bite marks.

Investigators soon came to believe that Ted Bundy was responsible for the killings. He initially refused to provide a dental impression, but with a court order, impressions were taken without warning to prevent him from filing down his teeth. The dental impression of Bundy’s teeth was matched to the photographs of the bite on Levy’s body.

Attempts to have the bite mark evidence thrown out of court were unsuccessful, and the dentist who took the initial impressions and photographs of Bundy’s teeth, Dr. Souviron, showed how the teeth matched the bite mark. Souviron went on to explain the creation of the bite marks.

Dr. Lowell Levine, a forensic dentist, explained how the bite had occurred. With the bite mark evidence, the state of Florida was able to sentence Ted Bundy to death by electric chair. Bundy was the first individual convicted on bite mark evidence in the state of Florida, and the bite mark was the only physical evidence that ever linked Bundy to his crimes.

Today, there are questions about the validity of bite mark evidence, even among skilled forensic dentists. Skin is a poor medium for a dental impression, and teeth are not a unique identifier.

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Fiber Analysis, 1979-1981/1982

Between the summer of 1979 and early summer 1981, 29 people, almost all African-American children, around Atlanta, Georgia were strangled by a serial killer. These murders are often called the Atlanta Child Murders. Bodies were found throughout the area, with relatively little care to the placement of the bodies after death. The victims were, however, connected geographically. The killer hunted in a relatively small area of the city.

The FBI became involved in early 1980 to assist in the investigation. Eventually, police began to stake out local bodies of water, believing that the killer might change his usual body drop sites to avoid detection. One of the officers heard the sound of something hitting the water. Several days later, the naked body of a man washed ashore.

They caught a man, Wayne Williams, driving away from the scene. They did not witness him dropping a body, but were able to collect dog hair and carpet fibers from the station wagon Williams drove. Williams claimed not to have stopped on the bridge, but this was in direct opposition to the witness testimonies of the police on stakeout that night.

Police were able to match fibers collected from Williams’ vehicle to fibers found on multiple victims of the Atlanta Child Killer. In addition, there was ample circumstantial evidence suggesting that Williams was the killer. He resembled a sketch of the killer, and had been seen with the last adult victim shortly before his death.

The fiber analysis was essential to Williams’ conviction; however, he was tried for only two of the murders. Local police believe he was responsible for nearly all of the killings. Williams was found guilty on February 27, 1982. Fiber evidence had successfully caught a killer.

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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.

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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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