Catherine Arcabascio, a law professor at Nova Southeastern University, said in a recent scholarly article a chimera can potentially leave misleading DNA deposits at a crime scene.
"If he is a chimera, the DNA from his saliva could, in theory, differ from the DNA in his semen, skin, blood or some other sample left at the scene."
Mr. Federico criticized Canadian courts for working on a dangerous assumption that DNA tests are accurate, unless the defence can prove otherwise. "The DNA party is over," he said. "It should be the Crown that has an onus to show that testing has been authenticated."
And no matter how careful Canadian labs are, once they send a DNA profile outside our borders, anything can happen. Under an Interpol agreement involving 187 countries, Canada has honoured 481 such requests in recent years.
But Mr. Federico said he worries about substandard lab conditions or skulduggery by a foreign police force keen to close a case.
The so-called Phantom of Heilbronn couldn't have been better named. After two years spent scouring the countryside for the presumed serial killer, German police discovered she didn't exist.
The bizarre tale began in 2007, when an individual's DNA profile began to show up at one crime scene after another. Eventually, 40 crimes - including 14 murders - were attributed to the Phantom.
Embarrassed analysts finally discovered that cottons swabs used by police at each crime scene to obtain DNA samples had been accidentally contaminated by a worker at the factory that made them. It was the worker's DNA that kept popping up, effectively linking the crimes.
Since June 30, 2000 the National DNA Database (NDDB) has been banking DNA profiles from crime scenes and convicted offenders. How it works:
DNA evidence is gathered from crime scenes and offenders
DNA IS COLLECTED FROM:
Offenders convicted of one of the 265 qualifying offences. Before 2008 there were only 59 qualifying offences.
Retroactive offenders serving sentences for serious offences committed before the DNA identification act came into effect.
Biological samples of blood, buccal cells (cells swabbed from the inside of the mouth) or six to eight hairs with the root attached are collected on a sample card along with the offenderís fingerprints.
DNA profiles are loaded into the Combined DNA Index System (CODIS), a software package provided for free by the Federal Bureau of Investigation and the U.S. Department of Justice.
SAMPLES RECEIVED TO DATE: 171,003
B.C. / 18,984
Alberta / 17,655
Sask. / 7,790
Ontario / 76,031
Quebec / 29,525
N.B. / 2,375
N.S. / 4,276
PEI / 380
Nfld. / 2,524
Yukon / 307
NWT / 1,071
Nunavut / 824
BY OFFENDER TYPE:
Young offenders / 22,071
Military offenders / 42
Adult offenders / 148,890
The most prolific offender in the database has been linked to 47 crime scenes
TOTAL CURRENTLY RETAINED:
CONVICTED OFFENDERS INDEX (COI) 158,493
More than one offence may be associated with a sample
Assault / 99,661
Break-and-enter / 23,967
Robbery / 23,019
Sexual offence / 31,253
Homicide / 5,622
Drugs / 4,804
Other* / 10,821
Data is cross- referenced
CRIME SCENE INDEX (CSI) 48,268
DURING THE 2008-09 THE NDDB RECEIVED MORE THAN 34,000 SAMPLES
Processing. Forensic labs prepare the biological samples for storage as DNA profiles.
600 to 700 samples per week go to the Offenders Index...
...the Crime Scene Index receives 80 to 100 samples a week
New samples are compared against DNA profiles from other crime scenes to identify links. Each upload of different convicted DNA profiles yields an average of 25 or 30 matches.
TOTAL NUMBER OF MATCHES: 13,291
'00-'01 / 25
'01-'02 / 227
'02-'03 / 560
'03-'04 / 1,242
'04-'05 / 1,312
'05-'06 / 2,323
'06-'07 / 2,313
'07-'08 / 2,300
'08-'09 / 2,989
Convicted offender identity information for matches is passed to investigators who will then determine whether charges should be laid.
TOTAL CASES ASSISTED: 206,467
Breaking and entering / 6,479
Sexual offence / 1,540
Robbery / 1,342
Assault / 806
Homicide / 730
Attempted murder / 279
Other / 327
*Other includes, but is not limited to: causing death or bodily harm by criminal negligence, failure to stop at the scene of an accident, kidnapping, hostage-taking, arson, fraud, counterfeiting, criminal organization, theft over $5,000, forgery, and intimidation.
TONIA COWAN/THE GLOBE AND MAIL
SOURCE: NATIONAL DNA DATABASE, RCMP, GRAPHIC NEWS