OF NEW DNA TEST IS CALLED INTO QUESTION
Laurie P. Cohen
The FBI has a powerful new weapon that gets its man nearly every
time it is deployed. One catch: In some cases, the weapon may demolish
the innocent along with the guilty. Another catch: Defendants can
use it, too.
called mitochondrial DNA testing, is a new way to analyze crime-scene
evidence. An important step beyond standard DNA testing, it has
been used by the Federal Bureau of Investigation only since August
1996 and has resulted in six convictions in six attempts.
be tried by a defendant for the first time in the long-running saga
of Jeffrey MacDonald, the former Army surgeon who was convicted
in 1979 of killing his wife and two daughters but who has always
insisted a marauding band of drug-crazed hippies did the deed instead.
If he is right, mitochondrial DNA testing of strands of hair found
under his daughters fingernails, and preserved all these years,
might yet show that he was not the killer.
most people outside of scientific circles have never heard of mitochondrial
DNA, it has been used to identify Czar Nicholas IIs bones
and to prove that the body in Jesse Jamess grave is truly
that of the outlaw. Since 1991, the military has also employed it
to identify soldiers remains.
of the Living
crime lab is responsible for moving the technique into the realm
of the living, despite scientific concerns about the accuracy of
the method. Thanks to the FBI, mitochondrial DNA testing has already
occurred in about 70 cases that havent yet reached trial.
days, viewers of Court TV know just about as much as the average
biology student about DNA, or deoxyribonucleic acid, which contains
a persons unique genetic code within the nucleus of each body
cell. With the exception of identical twins, no two individuals
share the same genetic code-making ordinary "nuclear"
DNA testing a popular means of identification in court cases.
1988, when nuclear DNA testing was first used by the FBI in criminal
trials, it has played a part in more than 30,000 cases nationwide.
Next year alone, the FBI predicts, it will employ the method in
as many as 2,500 cases.
nuclear DNA testing suffers from a major limitation: It cant
be used unless the evidence is fresh and in good shape; crucially,
there have to be cell nuclei present, and hair that has been pulled
away from its roots doesnt contain any nuclei.
mitochondrial DNA is located outside of a cells nucleus and
is much more plentiful than nuclear DNA. Indeed, a single cell will
have hundreds, even thousands, of mitochondria, tiny particles that
are responsible for converting food to usable energy. That means
more DNA can be extracted from smaller, older and less-well-preserved
fragments of evidence.
opens up whole new worlds for prosecutors, who sometimes have nothing
more to work with than a strand or two of hair or old skeletal remains.
The FBI labs small mitochondrial DNA unit in Washington, which
employs just two examiners and focuses on hair analysis, is now
gearing up to meet rising demand. "We have calls coming in
daily from prosecutors," says Joseph DiZinno, chief of the
scientific community, though, the much-sought-after forensic tool
is being greeted with skepticism. While juries may assume one type
of DNA is the same as another, the truth is that mitochondrial DNAwhich
is inherited from the mothers side onlydoesnt
provide the same kind of unique fingerprint as nuclear DNA. The
same mitochondrial DNA sequence is shared by siblings and their
mother and all of a persons maternal relatives for many generations.
And a 1993 British study found that even among unrelated people,
four out of 100 who were tested shared the same mitochondrial DNA
if a defendant is linked to crime-scene evidence through mitochondrial
DNA, there is a small but realistic possibility that he or
she had nothing to do with the crime. "The FBI is bringing
mitochondrial DNA into the courtroom and painting it with the same
reliability as other DNA typing," says one critic, William
Shields, a biologist at the State University of New York in Syracuse.
But, he adds, "It isnt as unique to an individual as
Edward Blake, a DNA expert with Forensic Science Associates in Richmond,
Calif.: "We dont know enough about mitochondrial DNA
in hair to be giving scientific testimony about it." Thats
also the view of the nations largest private DNA lab, Cellmark
Diagnostics Inc., in Germantown, Md. A company spokesman says further
study is needed before the lab will begin doing mitochondrial DNA
analysis on hair in criminal cases.
resistance doesnt faze the FBIs Dr. DiZinno. "We
wouldnt have gone on-line if were werent confident this
was a reliable technique," he says. Dr. DiZinno and Mark Wilson,
both former FBI hair examiners, began researching mitochondrial
DNA in 1992. By August 1996, they were ready to unveil it in a Chattanooga,
Tenn., courtroom. There, the technique helped win the conviction
of rape-and-murder defendant Paul Ware in a tangled case in which
much of the other prosecution evidence was weak.
was fortunate to be able to use Tennessee as its proving ground
for mitochondrial DNA testing. Tennessee is one of only six states
in which defendants arent entitled to pretrial hearings before
DNA evidence is admitted. In most states, such a hearing would have
subjected the FBI to tough questioning by defense lawyers and the
judge regarding scientific procedures and validity. Only then would
the judge have ruled on whether the evidence could be heard by a
jury. But in Tennessee, a state statute passed in 1991, before anyone
involved had heard of mitochondrial DNA testing, decreed that DNA
test results are always admissible in court.
legal system built on precedent, the successful application of the
technique in Tennessee was later used by the government as a wedge
to help it get mitochondrial DNA testing approved in states in which
pretrial hearings are required. "The FBI was happy to legitimize
mitochondrial DNA analysis in this state," says Barry Steelman,
a state prosecutor who worked on the Ware case, though Dr. DiZinno
says the FBI didnt have any control over where the first case
would be tried.
the Ware case, even when the defense has presented experts to oppose
mitochondrial DNA evidence, the FBI has prevailed.
Early this year, the FBIs mitochondrial tests linked a former
police officer to the 1993 murder of a man in Boone, N.C. After
years of delay, defense lawyer Bruce Kaplan says that mitochondrial
testing produced "the only physical evidence" linking
the defendant to the crime.
says use of the test wasnt a close call for the judge, even
though the defense argued that the method wasnt scientifically
sound. "The FBI comes in and testifies that mitochondrial DNA
has been previously admitted elsewhere and is accepted in scientific
circles, and that was that," Mr. Kaplan says.
have also been helped by the fact that not every defense lawyer
has attempted to challenge the method. "I didnt think
I was going to win an admissibility hearing, so I didnt ask
for one," says Fred Brown, the defense lawyer in a Waco, Texas,
case in which a defendant was accused of mailing a bomb to his estranged
wife. Postconviction appeals in these cases, objecting to the use
of mitochondrial DNA testing, havent yet been heard by appellate
their new forensic weapon to juries, FBI agents DiZinno and Wilson
wont say that mitochondrial DNA can be used to make a positive
identification. Instead, they speak of the frequency that a particular
DNA sequence appears in its current database of 1,043 individuals.
(Sandy Zabell, a Northwestern University math professor, has argued
in court, so far unsuccessfully, that the FBIs database is
too small and too narrowly drawn to lead to any conclusion at all.)
in standard DNA cases, FBI agents give jurors statistics indicating
the likelihood that a defendants DNA could have come from
another person. That likelihood is usually very small, on the order
of one in 200 billion.
the distinctions between nuclear and mitochondrial DNA appear to
be lost on many jurors. Indeed, the six jurors in mitochondrial
DNA cases who were interviewed for this article spokeincorrectly
of mitochondrial DNAs powerful capacity to identify suspects.
there a difference between kinds of DNA?" asks Linda Hicks,
a juror in the North Carolina case. "All I can say is the DNA
showed it pretty well matched" the defendant. Says Phillip
Summerlin, a hospital chaplain who was a juror in the Ware case,
"I thought mitochondrial DNA was a good way of identifying
people." Hank Hill, the lawyer for Mr. Ware, says jurors in
DNA cases have been heavily influenced by the O.J. Simpson case,
which involved standard nuclear DNA testing rather than mitochondrial
testing. He says they now tend to be uncritical of all DNA evidence
because they believe Mr. Simpson was wrongly acquitted. "After
O.J., most of middle-class America, which is where juries come from,
figure, If youve got DNA, you have to convict,
" Mr. Hill says. "They dont distinguish between
this DNA and that. Its all DNA to them."
hurts most criminal defendants, though, may be the only thing left
that can help Dr. MacDonald, who was the subject of the Joe McGinniss
book "Fatal Vision" and the made-for-TV movie that followed.
He has a chance to prove his innocence, after being shut down in
one appeal after another, because the government itself threw open
the door to a technique that courts otherwise might not have approved.
his conviction, Dr. MacDonalds lawyers had repeatedly tried
and failed to get courts to give Dr. MacDonald a new trial. The
odds of getting any court to listen were growing more difficult
with time; U.S. Supreme Court rulings in recent years had made it
all but impossible for prisoners who have been through the appeals
process once to have their cases reopened. But last April, the much-publicized
troubles at the FBI Laboratory gave Dr. MacDonald a fresh opening
to try again.
had always claimed that the intruders who had killed his family
were led by a woman wearing dark clothing, a floppy hat and a long,
blond wig. His lawyers tried to reopen the case in 1990 based on
the discovery of blond synthetic fibers they claimed must have come
from the womans wig. But the theory was shot down by Special
Agent Michael P. Malone, at that time the top hair-and-fiber examiner
in the FBI crime lab. In his affidavit in the MacDonald case, Mr.
Malone said the fibers he examined came from dolls and couldnt
have come from a womans wig.
course of his evaluation of the fibers in the MacDonald case, Mr.
Malone also examined a human hair from the crime scene that he said
was "forcibly removed and appears to have a piece of skin tissue
attached" to it. At the time, Mr. Malone said the hair couldnt
be microscopically identified and was too old for standard DNA testing,
which was the only kind then available.
in 1997, the new mitochondrial DNA techniquewhich could be
used on such a piece of evidence even if no cell nuclei were present
offered Dr. MacDonald a "last-gasp claim," says Andrew
Good, one of his defense lawyers. Meanwhile, in the wake of the
Justice Departments April report on the crime lab, Mr. Malones
credibility was now in question.
Department report, which criticized 13 FBI crime-lab analysts, was
particularly tough on Mr. Malone for giving inaccurate testimony
in an unrelated case. Meanwhile, a front-page article in The Wall
Street Journal also raised questions about the credibility of Mr.
Malones testimony in a number of cases, including Dr. MacDonalds.
The Journal article reported, among other things, that Mr. Malones
conclusion about the origins of the blond fibers found at the MacDonald
crime scene wasnt supported by other experts whom Mr. Malone
had interviewed or by textbooks available in the FBIs own
these revelations might influence a judicial panel, Dr. MacDonalds
lawyers again asked a federal appeals court to reopen the
case, this time seeking the right to conduct mitochondrial DNA testing
on crime-scene evidence. To help with this new approach, they brought
in DNA specialist Barry Scheck, best known for his role in cross-examining
the governments DNA expert in the O.J. Simpson case.
the court, without comment, granted the request. It was Dr. MacDonalds
first court victory of any kind in almost two decades. "It
is poetic justice that the same mitochondrial DNA testing that the
FBI is using as a sledgehammer to prosecute people is the way I
can now get back into court in my murder case," says Dr. MacDonald,
who is serving a life sentence in Sheridan, Ore.
test in his case is expected to take place early next year.
are due about one month later