September 20, 2005. Alejandra was raped. So was her
sister. They were lucky. Lucky to be left alive.
In the process of the rape, the rapist licked both of her
breasts. The Phoenix Police Department arranged for DNA swabs to
be taken from both of her breasts, along with
other samples collected using a sex (rape) kit.
18
samples for testing were eventually produced much later.
The Phoenix Police Dept. had several rapes on their hands with similar
characteristics at this point and suspected a serial rapist was at work.
September 22, 2005. (48 hours) Phoenix Police detectives
requested
the Phoenix Crime Laboratory perform analysis on ALL
items
in the sex kit. Both the above mentioned left and right
breast swabs are in this kit and have been preserved under a chain of
custody since their collection.
October 9, 2005. (2 1/2 weeks) The Crime Lab
identifies biological material (nucleated cells) present that
would be suitable for DNA testing on both the left AND the right breast
swabs, as well as the labia and vulva swabs --- areas where the rapist
had also licked.
The right breast swab
was
ordered tested by the Crime Lab. But inexplicably, the left
breast swab was not tested and instead was
placed in a freezer for storage untested.
Why some samples were ordered tested and not others is not
explained. This was a conscious decision because all other
specimens are ordered to be stored instead of tested.
November 23, 2005. (Two months) The right breast swab is finally
tested by the Phoenix Crime Lab. The results are marked
inconclusive. Inconclusive for non-victim DNA or inconclusive for
a sufficient number of distinguishing markers?
The test being performed is referred to as an STR ("star") test, and looks for matching "short tandem repeats."
[
adapted
from Wikipedia] A short tandem repeat (STR) in DNA occurs when a
pattern of two or more nucleotides are repeated AND the repeated
sequences are directly adjacent to each other and are repeated a unique
number of times per individual.
The STRs in use today for forensic analysis are all tetra- or
penta-nucleotide repeats (4 or 5 nucleotides long repeated), as these
give a high degree of error-free data while being robust enough to
survive degradation in non-ideal conditions.
CODIS (Combined DNA Index System = CODIS, the FBI
national DNA forensics database) uses
13 STR markers
each located on
different
human chromosomes, plus AMEL marker which is used to determine the
sex of the DNA donor being tested (markers designated):
* CSF1PO
* D3S1358
* D5s818
* D7s820
* D8S1179
* D13s317
* D16s539
* D18s51
* D21s11
* FGA
* THO1
* TPOX
* vWA
The analysis is performed by extracting nuclear DNA from the cells of a
forensic sample of interest, then amplifying specific regions of the
extracted DNA by means of a polymerase chain reaction. Once these
sequences have been amplified, they are resolved through capillary
electrophoresis, which will allow the analyst to determine the number
of repeats of the STR sequence in question are present.
So what is going on here? Why didn't all of the samples get
tested?
Ground was broken on the new
Phoenix Police Crime
Laboratory in October of 2004. It was completed and open for
business in 2005. Clearly their
CODIS data for
2004 and 2005 are essentially identical so they were working as a
testing laboratory somewhere before their new lab was completed.
So experience should not be an excuse.
Overworked? Overburdened with samples?
It's mission statement is "The central purpose for the existence of the
Phoenix Police Department
Crime Laboratory is to provide the highest quality forensic services
and scientific technical support to the criminal justice
community. Our vision is to make Phoenix the safest major city by
providing excellence in forensic science analysis."
From December 12, 2005 through June 26, 2006 (three to nine months)
eight people were murdered. It is believed their murderer may be
linked to prior rapes that have occurred in the same area under similar
circumstances.
During this time on February 16, 2006 (five months)
Phoenix
Police Detectives request the Phoenix crime lab again test ALL of
the biological material from the Alejandra rape case for DNA because of
“[t]he magnitude of all the possible related cases and the number of
victims....”
March 1, 2006, (5 1/2 months) the Phoenix Crime Lab
extracts 18 samples for DNA testing. No results are
presented, so were DNA tests done?
August 24, 2006 (11 months) After months of begging and threats
detectives within the Phoenix Police Department are finally given
permission
to request the
Arizona
Department of Public Safety's (DPS) Forensic Laboratory DNA test
all of the Alejandra rape specimens, including both the right and left
breast swabs. The request they make is for a more specific
y-STR ("why-star") DNA
test, is a STR test that is specific for males. But the markers
are confined to the single Y chromosome normally only found in
males. The advantage in rape cases is obvious...only the rapist's
DNA should react as long as the victim is female.
y-STR:: The DPS uses 16 y-STR markers each located on different areas
of the human Y-chromosome (male chromosome):
DYS456
DYS389I
DYS390
DYS389II
DYS458
DYS19
DYS385
DYS393
DYS391
DYS439
DYS635
DYS392
Y GATA H4
DYS437
DYS438
DYS448
Because only males have a Y chromosome, female DNA does not interfere
with Y chromosomal testing. Unlike STR testing, y-STRs are not unique
to each individual. The Y chromosome and therefor, the y-STRs are
inherited from their fathers, meaning that all paternally related males
will have the same y-STR profile.
The DPS not only runs their y-STR test on the right AND the left
breast, but labial and circumoral (surrounding the mouth) samples as
well. Their test examines matches at 16 different locations on the Y
chromosome. Profile matches are expected to occur no less than 1
in 333 times in the African-American population (such as Mark Goudeau).
Not a huge number in random probability, but fairly big.
This produced matches from the right breast and labial samples
consistent with Mark Goudeau's on file in the offender database,
meaning they could not exclude him at the time. Additionally
they picked up the rapist's DNA on the inside and outside of the
victim's shirt, and outside her purse that were similarly consistent
with Mark Goudaeu.
They also ran the (non-y) STR test as well on the left breast that the
Phoenix Crime Lab had not tested. This separate test STR has a
hit on the stored left breast sample consistent with the victim, her
sister
and Marc
Goudeau. They also tested the left breast sample with their y-STR
test producing a similar match to Mr. Goudeau. The combined odds
of a random match existing from both tests is over 360
trillion in the African American
population. The previously untested left breast sample nails it. [PS: I have my doubts about this odds claim. I doubt it is much over 1 in a billion and would love to see the statistical calculations.]
Further, Mr. Mark Goudeau's DNA sample was on file and available for
comparison at the time of the testing.
Extensive testing
report by DPS can be downloaded here. I should
note, even here the actual test results are not present.
Why the Phoenix Crime Lab failed to yield conclusive forensic STR
results on the right breast is unknown. Degraded sample seems
less likely since the DPS successfully created a profile in their y-STR
test. It is possible they lost at some point the DNA during
sample extraction and concentration or that phenol contamination
associated with the extraction process remained behind undetected to
contaminate and prevent the test reaction from working. Additionally, the rapist rubbed dirt on Alejandra's breasts in an effort to thwart DNA sampling. Soil contaminates are known to inhibit the STR PCR step unless they are well removed from the DNA. Since
the actual test results are not present
its failure is impossible to evaluate. In fact, none of the
actual test results are available...only a final interpretive result.
But the left breast -- which was positive by both STR and y-STR in the
DPS laboratory's hands -- was not tested despite repeated demands by
Phoenix Police that all specimens collected be tested as a priority,
and compatible biological material was noted as being present for
testing by the Phoenix Crime Lab scientists.
September 11, 2006 (one week shy of one year of terror the community
has been held hostage by a serial killer/rapist) the DPS Forensics Lab
reports the DNA test referred to as STR ("star") DNA was an State's DNA
Indexing System (SDIS) that feeds into CODIS
match
to suspect Mark Goudeau with the previously untested, but stored,
left breast swabs. [It would be more accurate to say the DNA test
did not rule Goudeau out as a suspect. Also note, the actual
match data is not present.]
Families of the murder victims are rightfully angry their loved ones
were not protected from this serial killer when the evidence linking
him to rape victims was already at hand before any killing took
place. As to why these samples were not tested by the Phoenix
Crime Lab after being requested at least twice to do so, hopefully
depositions will bring the reasons out.
An attorney for three of the murder victim's families,
Marc Victor, who has
brought suit on behalf of these families against the City of Phoenix
says he is outraged that the police were hampered in their
investigation by the failure to get their evidence tested in a timely
and apparently accurate manner by the Phoenix crime lab. And that
it is unconscionable that it took so long for the specimens to finally
be transfered from the Phoenix Crime Lab for testing at an alternate
nearby DPS forensic facility.
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