Blood, Bullets, and Bones Page 16

  Around the same time, it was discovered that humans have different types of blood. Since at least the 1600s, doctors had tried to save the sick and wounded through blood transfusions. Whereas this worked for some patients, most would go into shock and die. Scientists discovered that human blood sometimes reacted to the blood of another human in the same way it reacted to animal blood: by clotting. It was clear that some people’s blood was incompatible with others’. Austrian scientist Karl Landsteiner showed why. He dropped some of his own blood into test tubes with various other colleagues’ blood. Some mixtures resulted in clumping, while others did not.

  This test resulted in the discovery of the human blood types we still know today. Typing depends on the antigens and antibodies people have in their blood. An antigen is a protein present in red blood cells. An antibody is a protein in the blood plasma that reacts to certain antigens. Type A blood has A antigens and B antibodies. Type B blood has B antigens and A antibodies. When type A and type B blood mix, the antibodies and antigens react, and the blood clumps. Type AB blood has antigen A and B, but neither type of antibodies, and so doesn’t clump when it mixes with either type of blood. That means if you have type AB blood, the rarest type, you can accept blood from any donor. This is known as being a universal recipient. Type O is the opposite of type AB blood. It has no antigens. A type O donor, known as a universal donor, can donate to those with type A, B, AB, or O blood, but can accept blood only from type O donors. (That’s why, on TV shows, doctors call for type O blood for a patient who needs a fast transfusion but whose blood type is unknown.) However, these blood types are just a starting point. There are also blood types within the broad categories, and so blood transfusions are a little trickier than that.

  In 1915 Dr. Leon Lattes of the Institute for Forensic Medicine in Turin wondered if blood type could be used to solve crimes. In one case, he was able to show that a suspect was innocent. Aldo Petrucci was a repeat offender found with blood on his coat after a murder. He claimed to know nothing of the crime and said the blood was from a nosebleed. Lattes took blood from the victim, blood from Petrucci’s coat, and blood from the suspect. Petrucci’s blood type, and the blood from the coat, were type O. The victim’s blood was type A. That cleared Petrucci of the crime. A blood type match could also be used to draw out a confession. But in truth, the likelihood of having type A, B, AB, or O blood is 40 percent, 11 percent, 4 percent, and 45 percent, respectively, in America. So, with the exception of AB blood, the presence of a certain blood type doesn’t narrow the pool much.

  Later, it was learned that in about 80 percent of people, blood type is also expressed through bodily fluids, such as tears or saliva. These people are known as secretors. This was cutting-edge science in 1939, when an elderly man was found murdered in Bournemouth, on the south coast of England. Walter Dinivan was a wealthy man whose grandson and granddaughter lived with him. They went to a dance one night and returned to find their grandfather badly beaten. He was taken to the hospital and died soon after.

  There was evidence of a robbery, and cigarettes and a curler were found on the scene. The grandchildren told the Dorset police that their grandfather would sometimes hire prostitutes, which might have explained the cigarettes and curler. Scotland Yard detective Leonard Burt was called in to assist with the case, and his instincts told him that the scene was staged. For instance, a cigarette lying on a couch cushion had to have been put out before it was casually dropped there (which it was made to look like). Otherwise, it would have burned the fabric. Furthermore, prostitutes questioned about the incident laughed at the old-fashioned curler; it was the kind elderly ladies used.

  England had been late to establish a police laboratory—the first was created in 1934 in Nottingham. It came in useful with this case. Investigators had the saliva on the cigarettes tested for blood type, and as luck would have it, the smoker was a secretor with the rare AB type. A staged crime scene points to a suspect who knew the victim, and police began investigating Walter’s friends. Burt interviewed Joseph Williams, who was over seventy years old, but figured him too old to have beaten the victim so badly. Burt’s opinion changed when a prostitute told them that the usually broke Joseph had suddenly come into a lot of cash.

  Police confronted Joseph, and he admitted to going to Walter for a loan but balked at the suggestion of murder. They tried a different tack. Burt told Joseph not to worry. He was no longer a suspect. Burt even bought Joseph a beer at the pub and offered him cigarettes. If you’ve watched even a few detective shows, you know that it was all a trick. Police had the cigarettes tested—and sure enough, Joseph had the rare type AB blood. His ex-wife was also tracked down, and she said that she used the same type of curler found on the scene. At the trial, however, the defense called the saliva evidence unreliable, and Joseph was acquitted. After the verdict, he admitted his guilt to his defense attorney, who shared the admission only after Joseph’s death.

  The case could be repeated in modern times, only with the saliva being tested for DNA rather than blood type. And in the early days of DNA, the jury might have balked at that evidence, too. But in fact, DNA testing, assuming the sample size is large enough, is considered the most reliable forensic evidence available. When it is present, DNA evidence can indicate almost without question that the suspect was at the crime scene.

  The structure of DNA was discovered in 1953 by James Watson, Francis Crick, Rosalind Franklin, and Maurice Wilkins. It was a watershed event, revealing the very recipe for all life on earth. DNA basically functions like this: The human body contains trillions of cells, and each cell contains a person’s entire genome (all of their DNA). DNA is shaped like a long, twisted ladder, or double helix. Each ladder rung has two letters—either A and T or G and C (the same two letters always pair up). These letters stand for the chemical compounds adenine, thymine, guanine, and cytosine. Along each side of the ladder, the letters make three-letter words. Several words together make a gene. The genes are instructions for building proteins—which in turn are the building blocks of the human body.

  DNA’s role in forensic science would not come until decades after its discovery. In the 1980s, Alec Jeffreys of the University of Leicester developed a blood test to determine a person’s DNA profile and suggested that it could be used in criminal investigations. The test has changed through the years. Today, it works like this: All human genomes are 99.9 percent alike, which explains why all humans are remarkably similar to each other. But just as no two people are exactly alike, no two genomes are exactly alike. Looking at the same place on a genome, one person may have a sequence of letters, such as GCAAT, repeat five times, whereas in another person, they repeat fifteen times. The five-time repeat may occur in, say, one out of twenty people. A second section of the genome is also examined, and a certain variety of that sequence may also occur in one in twenty people. Together, the two sequences occur in one in four hundred people. Add a third sequence, and you have a set of sequences that occurs in one in 8,000 people. (That is just a hypothetical example to show how the sequences add up to be less and less common in the population.)

  Structure of a DNA double helix

  The US standard is to test thirteen sections of DNA, and together, those thirteen can only be found in one in a trillion people—more than the Earth’s entire population. (The FBI recently recommended that even more sections of DNA be tested—twenty in all.) That’s how investigators can link a DNA sample to just one suspect. Of course, no test is foolproof, but DNA testing is remarkably accurate and far more specific than a blood type test, which may only narrow down the pool to 45 percent of the entire population.

  DNA evidence was first used to solve a murder in 1987, but the case began several years earlier. On November 21, 1983, fifteen-year-old Lynda Mann walked to a friend’s home in the small village of Narborough, England, at around seven thirty p.m. Later that night, her parents learned that she had never come home. They searched the village but couldn’t find Lynda. At seven twenty the n
ext morning, a worker at the local psychiatric hospital made a heartbreaking discovery: Lynda, raped and strangled to death. Police suspected one of the inmates, but there was no evidence that any had left the hospital that night. After three years, the case was still unsolved.

  Then tragedy struck again. On July 31, 1986, fifteen-year-old Dawn Ashworth walked from her home in Enderby to a friend’s house in the nearby village of Narborough. She never returned home. After a long search, she was found in a field near Ten Pound Lane, also raped and strangled to death. The semen revealed that the blood type in both cases was the same.

  Police suspected a seventeen-year-old boy with learning disabilities. He said he’d walked with Dawn part of the way to her friend’s house. He didn’t remember harming her but said perhaps he had gone crazy and done so. He later denied the possibility and never confessed to the first murder. Moreover, his mother said he had an alibi. His father had read about Dr. Alec Jeffreys and DNA testing and asked his son’s attorney about it. The police agreed to test the teenage suspect’s DNA, thinking that perhaps it would even link him to the first murder.

  Jeffreys compared the DNA from the semen samples to the DNA in the young suspect’s blood. The suspect’s DNA was different from the semen samples, but the semen samples matched each other. The teenager was not the killer. But the two girls had been murdered by the same person. With the new forensic tool of DNA, investigators launched a revolutionary manhunt. They asked every adult male—4,500 in all—in the village and surrounding villages to volunteer a blood sample for testing. Those with type A blood would have their samples further tested for the DNA profile. DNA testing was new—and slow. After eight months, the testing had found no matches. But while the high-tech testing occurred, a break in the case came from an old-fashioned source: gossip. A baker named Ian Kelly told coworkers at a pub that, using a fake passport, he had given blood on behalf of another man. That man was Colin Pitchfork. Pitchfork had explained to the friend that he’d already given blood on behalf of another man and would get in trouble if he showed up again. One of the coworkers shared this information with the police, who began investigating Pitchfork. His DNA was a match, and he confessed to both murders. He received two life sentences but was to be eligible for parole. In April 2016, Pitchfork was denied parole but recommended for a move to a lower-security prison.

  A sexual assault evidence collection kit, commonly called a rape kit

  The use of DNA evidence spread to America, and in 1994, federal law led to the creation of a national database for DNA—the FBI’s Combined DNA Index System (CODIS). When bodily fluid, such as semen collected as part of a rape kit, is left at a crime scene, it is tested for DNA type. That DNA profile is entered into CODIS. CODIS also contains DNA profiles from people who have been convicted of or arrested for serious crimes. That varies from state to state. The federal government and twenty-eight states allow the DNA testing of a suspect arrested for a serious crime. The other twenty-two states take samples only after a person is convicted of a crime. That’s a big difference, as a suspect is presumed innocent, while a convict is not. But the US Supreme Court recently upheld a state law allowing DNA samples to be taken after an arrest for a serious crime—not just after a conviction. The Court ruled that, like fingerprinting and photographing, a cheek swab for DNA testing is a reasonable part of an arrest under the Fourth Amendment, the right Americans have to not be searched or have their property searched without reason (evidence that they may have committed a crime). Legal experts believe that the Supreme Court ruling may lead other states to collect DNA samples during arrests.

  Investigators are automatically notified by CODIS when DNA in the database matches DNA from a crime scene. So DNA taken from a suspect in a new case may lead to an old case being solved. In the case that led to the Supreme Court ruling, Alonzo King Jr. of Maryland was arrested in 2009 on an assault charge. A DNA sample was taken, which matched a DNA sample from a 2003 unsolved rape case. He was convicted of that crime. He argued that his right to privacy was violated when his DNA sample was taken before he was convicted of a crime. The Supreme Court’s ruling, of course, said that it wasn’t. (If a person is exonerated of a crime, they can have their DNA removed from the database, though it is a difficult process.)

  When DNA testing first became available, it broke open a lot of cold cases. Chris Harvey became the director of cold case homicide investigations for Fulton County, Georgia, in 2005, after a federal grant allowed the county to revisit murder cases involving sexual assaults. Rape kits including semen samples were still on file for these cases. The samples had been taken to determine blood type, which could rule out suspects. Investigators didn’t know at the time that these samples would one day do much more. Now Harvey’s team could test for DNA and match that to people in the prison system (whose DNA samples had been taken due to their convictions). The results of DNA testing on the semen samples fell into four categories: no DNA profile was available (because the DNA had deteriorated over time), the profile was partial, the profile was complete, or the profile was complete and there was a CODIS match. The last category was the best-case scenario.

  Investigators would then visit the suspect—who was often still in prison for the other offense—and ask in as many ways possible whether he knew the victim. If he denied it, that was all the better for investigators, as the suspect then had no explanation for his DNA being found at the scene. Harvey described the moment in which the suspect was told of the DNA match: “You’d go into the prison and they’d have no idea why you were there. And you’d watch their face change. They’re thinking, ‘Holy crap. I thought I’d gotten away with that.’ It was like someone reaching out from the grave.”1

  If there was a full profile, but no CODIS match, the investigators would revisit each leading suspect and ask for a DNA sample. If the suspect refused, investigators could either seek a search warrant or go into stealth mode, following a suspect and obtaining a glass from which he drank or a cigarette that he smoked. In one case, they followed a suspect to a restaurant and asked the waitress for his glass. They found not one but three types of DNA on the glass. None matched the sample from the crime scene.

  Even though the new convictions couldn’t bring back the victims, the families were grateful for any resolutions. Although, as Harvey pointed out, in many murder cases the victim had no family. He or she lived a lonely life, and often a dangerous one involving drugs and prostitution. He said that resolving those cases was important to the detectives for that very reason. “Nobody cared about this person,” he said. “Somebody had to stand up and be for this person.”2

  CODIS now contains 10.1 million DNA profiles from convicted criminals and 1.3 million more from arrestees. In 2013 alone 200,300 DNA matches were obtained through CODIS, which helped in 192,400 investigations nationwide. Just as DNA evidence has brought justice for victims, it has given those convicted a chance to prove their innocence. Many, including Johnnie Lee Savory, were just teenagers when they were sent to prison.

  At age fourteen, Johnnie was accused of killing nineteen-year-old Connie Cooper and her fourteen-year-old brother, James Robinson. The two were found stabbed to death in their Peoria, Illinois, home on January 18, 1977. At first, the police thought Connie might have been raped, and that she and James were murdered so that they wouldn’t identify her attacker. She was found with her nightgown pulled up above her waist, her underwear torn, and blood on the bed. A rape kit tested positive for semen. A week after the murders, however, the police dropped this theory and focused their investigation on James’s friend Johnnie, with the motive instead being anger that erupted during a karate match with James.

  Johnnie had had a tough life. His mother died when he was a baby, and he was being raised by his father. The police visited Johnnie at the end of one school day, and brought him to the police station, where the interrogation lasted until ten p.m. The next day, the interview ran from ten thirty a.m. to eight p.m. At first, Johnnie told police that he had visited
James the day before the murders. The teen eventually confessed, but later recanted the confession.

  Nevertheless, the trial centered on Johnnie’s confession. But the evidence didn’t match up. Hairs found in the two victims’ hands were not similar to Johnnie’s. Pants found in his home had type A blood type—Connie’s blood type—but they were several sizes too large for Johnnie. His father, YT Savory, testified that the pants belonged to him, and that he had cut his leg a few weeks before. YT also had type A blood (along with 40 percent of the US population), and hospital records corroborated his injury. A pocketknife with a bloodstain was found in a pants pocket, but YT said he had used the blade to remove his stitches. Johnnie was convicted. But on appeal, a judge ruled that police had coerced his confession. A new trial was ordered.

  At first, the state’s attorney planned to drop the case. There simply wasn’t enough evidence to convict Johnnie without the confession. But soon, three new witnesses came forward—Frank, Tina, and Ella Ivy. The siblings had been interviewed by the police prior to the first trial but hadn’t testified. At the time, they’d said that Johnnie had only told them that he knew that James and Connie had been murdered—not that he had done it. Now, the siblings said that Johnnie had also confessed to stabbing the two victims. (The Ivy siblings would later recant their testimonies.)

  Prosecutors also focused on what Johnnie had told the police prior to his confession. He had said that on January 17, he’d been playing karate with James. They’d moved the TV to the floor so that it wouldn’t get kicked over, and they’d cooked corn and hot dogs. But the police believed all that actually occurred on January 18, the day of the murders. The victim’s mother said that on the morning of the eighteenth, she had cooked corn and hot dogs and left the food on the stove. When she came home and found the bodies, the television was on the floor and the kitchen in disarray. Police said that Johnnie’s description of the home from January 17 was in fact a description of the crime scene. They theorized that during the karate match, he had flown into a rage. Of course, it’s possible that in the process of eliciting the confession, police had provided Johnnie with information about the crime scene, and he was repeating details he had been told. Nevertheless, Johnnie was convicted again.