In 1997, Wisconsin's State Crime Laboratory established a DNA fingerprint registry and that same year the Milwaukee Police Department began reviewing all unsolved rape cases with physical evidence available for possible matching. They found fifty-three, and in six months they had scored eight cold hits against DNA fingerprints from felons already serving time. In one case, the identification was made so late the arrest warrant was issued only eight hours before the statute of limitations kicked in.
Among the cold cases, the State Police Department was also to establish evidence of a serial rapist – three separate assaults, three separate semen samples, the DNA fingerprints of all of them pointing to the same man. With the statute of limitations soon to take effect, Norm Gahn, an assistant district attorney, faced a dilemma. There was not enough time to identify the assailant in the database, but he could not draft a warrant without the suspect's name. Gahn hit on a clever strategy. The Wisconsin criminal code held that in the event a suspect's name was unknown, a valid warrant could be issued on the basis of "any description by which the person to be arrested can be identified with reasonable certainty." Surely, Gahn reasoned, any court would accept a DNA fingerprint as identifying someone by that standard. He made out the warrant: "State of Wisconsin vs. John Doe, unknown male with matching deoxyribonucleic acid (DNA) profile at genetic locations D1S7, D2S44, D5S110, D10S28, and D17S79." Despite Gahn's ingenuity, though, this John Doe still has not been caught.
Meanwhile the first challenge in court of a John Doe DNA warrant came in Sacramento, where one man, called the "Second Story Rapist," was believed to have committed three rapes over several years. Anne Marie Schubert, a local prosecutor, followed Gahn's lead in filing a John Doe DNA warrant just three days before the statute of limitations was to take effect. But she had to satisfy the requirements of her own jurisdiction, in particular the California law requiring that a warrant identify the suspect with "reasonable particularity"; toward this end she specified: "unknown male . . . with said genetic profile being unique, occurring in approximately 1 in 21 sextillion of the Caucasian population, 1 in 650 quadrillion of the African American population, 1 in 420 sextillion of the Hispanic population." Shortly after the warrant was issued, when John Doe's DNA fingerprint was entered into the state database, it turned out to match that of one Paul Eugene Robinson, who had been arrested in 1998 for violating parole. The warrant was amended with "Paul Eugene Robinson" in the place of John Doe and his STR markers, and Robinson was duly arrested. His attorney argued that the first warrant was invalid as it did not name Robinson. Fortunately, the judge upheld the validity of the warrant, remarking that "DNA appears to be the best identifier of a person that we have."
In the wake of the publicity stirred by these successful "John Doe DNA" warrants, many states have amended their rape statutes to permit an exception when DNA evidence is available.
The reach of DNA fingerprinting now even extends beyond the grave. In 1973, Sandra Newton, Pauline Floyd, and Geraldine Hughes, all teenagers, were raped and murdered in South Wales. Twenty-six years later, DNA fingerprints were prepared from samples saved from the crime scenes, but unfortunately the National DNA Database yielded no matches. So, rather than looking for an exact match, the forensic scientists looked for individuals whose DNA fingerprints indicated that they might be related to the murderer. They thus identified a hundred men, furnishing the police with a wealth of leads in light of which to reassess the masses of information that they had collected during the original investigation. Through a combination of state-of-the-art DNA forensics and good old-fashioned detective work they found a trail leading to one suspect, Joe Kappen. The only trouble was that Mr. Kappen had died of cancer in 1991 – what was to be done?
In 1999 Kappen was exhumed and fingerprinted. And the fingerprints indeed matched those from DNA recovered from the three victims. Cancer may have exacted the ultimate price before the law could find him, but at least the girls' families had the long-postponed satisfaction of knowing his name.
DNA fingerprinting has solved mysteries involving bodies much more illustrious than Joe Kappen's. Take the extraordinary story of the Russian royal family, the Romanovs.
In July 1991, a small group of detectives, forensic experts, and police assembled in a muddy, rain-soaked clearing in the forest at Koptyaki, Siberia. Here, in July 1918, eleven bodies had been hurriedly buried. They were the remains of Tsar Nicholas II and Tsarina Alexandra; their son, Alexis, heir to the throne; their four daughters, Olga, Tatiana, Marie, and Anastasia; and four companions – all of whom had been brutally murdered a few days before, Anastasia still holding Jemmy, her pet King Charles spaniel, as she met her end in a hail of bullets. The killers initially tossed the bodies down a mine but, fearing discovery, recovered them the next day before finally burying them in that pit in the forest.
The grave had first been discovered in 1979 thanks to the detective work of Alexander Avdonin, a geologist obsessed with learning the fate of the tsar's family, and the filmmaker Geli Ryabov, who, having earned the privilege of making an official documentary of the Revolution, had gained access to relevant secret archives. In fact, it was a report written by the chief murderer for his bosses in Moscow that led Avdonin and Ryabov to the gravesite. They found three skulls and other bones. But as the chokehold of the Communist Party was then as tight as ever, they rightly realized they would do themselves no favors by drawing attention to the Bolsheviks' butchery of the royal family. They reburied the remains.
With the thawing of the political climate that culminated in the demise of the Soviet Union came the opportunity Avdonin and Ryabov had been waiting for. So it was that picks and shovels were again wielded in the forest clearing.
The exhumed remains – a total of more than one thousand pieces of skull and bone – were taken to a Moscow morgue, where the painstaking process of reassembling and identifying the skeletons began. There was an immediate surprise. The murdered were known to have numbered eleven, six females and five males, but the grave contained the bones of only nine bodies – five female and four male. It was clear from the skeletal remains that the missing bodies were those of Alexis (fourteen at his death) and Anastasia (who had been seventeen).
The claims of identification were viewed with some skepticism, especially as there had been disagreement between the Russian scientists and an American team that had come to assist. And so in September 1992, Dr. Pavel Ivanov brought nine bone samples to Peter Gill's laboratory at the British Forensic Science Service. Gill and his colleague David Werrett had been coauthors of the first paper Alec Jeffreys published in this field and had since established the Forensic Science Service as the UK's premier laboratory for DNA fingerprinting.
Gill had developed a DNA fingerprinting method using mitochondrial DNA (mtDNA), which, as we saw in the analysis of Neanderthal mtDNA, has a special advantage in cases when DNA is old or difficult to obtain: it is far more abundant than the chromosomal DNA from the nucleus.
Gill and Ivanov's first task was the delicate job of extracting both nuclear and mtDNA from the bone samples. The analysis showed that five of the bodies were related and that three were female siblings. But were these the bones of the Romanovs? In the case of the Empress Alexandra at least, an answer could be found by comparing the mtDNA fingerprint from the bones thought to be hers with an mtDNA fingerprint from her grandnephew, Prince Phillip, the Duke of Edinburgh. The fingerprints matched.
It was rather more difficult to find a relative for the tsar. The body of the Grand Duke Georgij Romanov, his younger brother, dwelt in an exquisite marble sarcophagus deemed too precious to open. The tsar's nephew refused to help, still bitter over the British government's refusal to grant his family refuge at the onset of the Revolution. A bloodstained handkerchief was known to exist in Japan, one the tsar had used when he was attacked by a sword-wielding assassin in 1892. Gill and Ivanov secured a narrow strip of it but found that over the years the relic had been contaminated beyond usefulness with the DNA of ot
hers. It wasn't until two distant relatives were finally found that the mtDNA fingerprint was confirmed as the tsar's.
But the analysis had yet one more surprise in store: the mtDNA sequences from the presumed tsar and his modern relatives were similar but not identical. Specifically, at position 16,169, where the tsar's mtDNA had a C, that of the two relatives showed a T. And further testing revealed only further complications. The tsar's mitochondrial DNA was actually a mix of two types, both C and T. This unusual condition is called "heteroplasmy" – the coexistence within a single individual of more than one mtDNA type.
A few years later the worries of all but the most committed conspiracy theorists were finally put to rest. The Russian government finally agreed to crack the sarcophagus and provide Ivanov with a tissue sample from Georgij Romanov, the tsar's brother. The grand duke's mitochondria showed the very same heteroplasmy as those found in the bones from the pit. Those bones were without question the tsar's.
But what of the legendary Anastasia, whose skeleton was never recovered from the grave in the forest? There has been no lack of pretenders to the Romanov line, and among these none was more persistent than one Anna Anderson, who asserted for a lifetime that she was the lost grand duchess. She'd first made the claim as early as 1920 and went on to become the subject of many books as well as the film Anastasia, in which, played by Ingrid Bergman, she was indeed found to be the grand duchess. When Anderson died in 1984, her identity was still in dispute, but as the claims and counterclaims of her supporters and critics continued, the means for a resolution were at hand.
Anna Manahan (Anna Anderson's married name) had been cremated, making tissue retrieval from her remains impossible. But an alternative source of her DNA was discovered: in August 1970, she had undergone emergency abdominal surgery at the Martha Jefferson Hospital in Charlottesville. Tissue removed during the operation had been sent to a pathology laboratory where it was prepared for microscopy, and where, twenty-four years later, it was still filed away. After an appropriately Byzantine series of court cases over access to the specimen, Peter Gill traveled to Charlottesville in June 1994 and departed with a little preserved slice of Anna Manahan.
The results were crystal clear. Anna Anderson was related neither to Tsar Nicholas II nor to the Empress Alexandra. But in the wake of such a long odyssey, it is perhaps not surprising that some chose to ignore the DNA and believe what they would: the myth that Anna was Anastasia still lives on.
The fate of the Romanovs and Anna Anderson may be the stuff of fairy tales, remote from most of our lives, but DNA fingerprinting is ordinarily applied to grim realities painfully all too close. One of the most awful tasks facing investigators after a violent catastrophe like a plane crash is the identification of bodies. For various reasons – to permit the issuing of a death certificate, for instance – the law requires that it be done. And no one should underestimate the desperate emotional need of families to bury their loved ones with proper ceremony; for most of us, respect for the dead requires the recovery of their remains, however fragmented, and this task depends on positive identification.
In 1972, an American warplane believed to have been piloted by Michael Blassie was shot down during the Battle of An Loc in Vietnam. Remains were recovered from the crash site, but an inadequate forensic examination in 1978 based on blood type and analysis of the bones indicated that they were not Blassie's. The anonymous bones were labeled "X-26, Case 1853," and in a solemn ceremony attended by President Reagan, they were laid to rest in the Tomb of the Unknowns at Arlington National Cemetery. In 1994, CBS News picked up a story by Ted Sampley in the U.S. Veteran Dispatch, claiming that X-26 was Blassie. When the subsequent investigation by CBS uncovered evidence corroborating Sampley's claim, Blassie's family petitioned the Department of Defense to examine it. This time mtDNA fingerprints from the unknown's bones were found to match those of Blassie's mother and sister. Twenty years after his death, Blassie came back to St. Louis. Standing beside the gravestone, his mother was able to say, "My son is home. My son is finally home."
The Department of Defense has since established the Armed Forces Repository of Specimen Samples for the Identification of Remains. Blood samples are taken and DNA isolated from all new members of the military, both those on active duty and reservists. By March 2001, the repository contained more than 3 million samples.
I was on my way to my office when I heard that a plane had crashed into one of the World Trade Center towers. Like many others, I assumed initially it was an accident – anything else was unimaginable. But all too soon, when the second plane hit the other tower, it was apparent that a criminal act of the most ghastly kind had been perpetrated against thousands of innocent people. No one who watched that day is likely ever to forget the images of people leaning out of windows high on the towers, or falling to their deaths. And we were not shielded from the tragedy's immediate toll even on the tranquil campus of Cold Spring Harbor Laboratory, thirty miles from Manhattan: two of our staff lost sons that day.
The final loss of life has been reckoned at 2,792 – an extraordinarily low number considering that as many as 50,000 may have been in the towers at the time of the attack. Nevertheless, given an event of such cataclysmic force, one can expect to find few bodies intact, much less alive. And so the search for survivors was transformed with a tragic inevitability into the hunt for remains; a million tons of mangled steel, pulverized concrete, and crushed glass were sifted for any human part they might yield. Some 20,000 were found and taken to twenty refrigerated semi trucks arrayed near the medical examiner's office. Since the beginning of this herculean forensic effort, many identifications have been made using dental records and conventional fingerprints, but as the easy cases are closed, increasingly the load shifts to DNA analysis. For comparison with all genetic traces from the site, relatives have supplied either samples of their own blood or items like the toothbrushes and hairbrushes of the dead, any possession that may have picked up even a few of its owner's cells from which DNA could be extracted. The task of carrying out the DNA fingerprinting has fallen to Myriad Genetics in Salt Lake City and Celera Genomics, both of which are accustomed to analyzing DNA on an enormous scale. But even with the very latest technology, this is a slow and painstaking process.
It is a common human desire to know one's forebears: who they were and where they came from. In the United States, a nation built by generation after generation of immigrants, the longing is especially intense. In recent years, the genealogical craze has been aided by the World Wide Web, which also supplies us with an informal measure of the phenomenon's dimensions: a Google search for "genealogy" yields over 10 million hits (a search for "DNA" gets you only 5 million). By comparing the fingerprints of individuals, DNA makes possible the highly specific sort of genealogical inquiry that Gill and Ivanov carried out to uncover, for instance, Anna Anderson's relationship to the Romanovs (none). But genealogies can also be constructed at a broader level, finding connections by comparing the DNA fingerprint of an individual with those of whole populations.
At Oxford, Brian Sykes used DNA analysis to delve into his own genetic history. Knowing that both surnames and Y chromosomes are transmitted down the male line, he surmised that all men born with the same surname should also have the same Y chromosome – the one belonging to the very first man to take that name. Of course, this linkage of Y chromosome and surname breaks down if a name should arise independently more than once, if men change the family name for one reason or another, or if many boys take the name of a man other than their biological father (a lad secretly sired by the milkman, for instance, would likely wind up with the surname of his mother's husband).
After contacting 269 men called Sykes, Professor Sykes managed to collect 48 samples for analysis. He found that about 50 percent of the Y chromosomes were indeed identical to his own "Sykes" chromosome; the rest bore evidence of conjugal lapses on the part of more than one Mrs. Sykes of generations gone by. Because the origin of the name is documented
and can be dated to around seven hundred years ago, it is possible to work out the per-generation rate of infidelity. It averages out to a perfectly respectable 1 percent, suggesting that 99 percent of Sykes wives in every generation managed to resist extramarital temptation.
When Sykes set up a company to market genealogical DNA fingerprinting services, one of his first clients was the John Clough Society, whose members trace their ancestry back to a Briton of the same name who emigrated to Massachusetts in 1635. The society even knew that an ancestor of his, Richard, from the Welsh line of the family, had been knighted for his deeds on a crusade to the Holy Land. What they lacked, however, was any historical proof to link their families to those on the other side of the Atlantic. Sykes's company analyzed Y chromosome DNA from the Massachusetts Cloughs and from a direct male descendant of Sir Richard; the two were indeed identical – vindication for the Massachusetts branch. But not all the American Cloughs were as lucky; society members from Alabama and North Carolina were found to be unrelated not only to Sir Richard but to the Massachusetts Cloughs as well.
Dna: The Secret of Life Page 31