Jeff Thompson
Assistant Laboratory Director
Serology/DNA Unit
Scientific Investigation Division
Los Angeles Police Department
ASCLD 42nd Annual Symposium
April 29, 2015
2008-2009
 Backlog of (unrequested) kits: 6,132
 Average # of kits received per month: ~105
 Number of bench DNA analysts: ~10
◦ Few kits requested & tested
◦ Extensive use of outsourcing
◦ Turnaround time: >>120 days

Changes & Expectations
◦ New hires since 2008: 40+
◦ Goals
 Turnaround time <90 days
 Test ALL kits without outsourcing

DNA testing determined by
◦ Sperm rating
 Microscopy is time-consuming (especially if the
kit is negative & includes slides generated by
SART nurse)
◦ Presence of nucleated epithelial cells on dried
secretions
 E. Cells probative or not?
 Perioral swab?
 Thigh swab?
 Minor’s left hand?

Medical Report
◦ Information not always consistent with request
submitted by Detectives
 Which one do you trust?
◦ Do you screen only the probative items based on
the allegations?
 What if victim reports Loss of Consciousness/Loss of
Memory (LOC/LOM)?
◦ What do you do if the alleged act is digital
penetration? Groping?

Inspiration from Georgia Bureau of
Investigation
◦ Switched from microscopy to Quantifiler
Duo for screening rape kits
◦ Achieved significant gains in screening
productivity
Differential/NonDifferential extraction
(lyse e. cells)
Return to SAEK to
sample swabs
Document SAEK
Contents & Sample
Swabs
Microscopy
GBI
Sexual Assault
Evidence Kit (SAEK)
3µL aliquot to slide
“pre-extraction”
Microscopy
3µL aliquot to slide
“post-extraction”
Sperm digest
EZ1 Cleanup
Water Extraction
Quant Duo
Male DNA
Sexual Assault
Evidence Kit (SAEK)
Differential/NonDifferential extraction
(lyse e. cells)
Return to SAEK to
sample swabs
Microscopy
3µL aliquot to slide
“post-extraction”
Sperm digest
Document SAEK
Contents & Sample
Swabs
Microscopy
3µL aliquot to slide
“pre-extraction”
Water Extraction
EZ1/QiaSymphony
Quant Duo
Cleanup
Male DNA

Male Screen Detail Program (MSD) Goals
◦ Increase efficiency of screening
 Quantifiler Duo
 Touch SAEK one time only
◦ Lower turn around times
 Write one report
◦ Expand duties of new hires
 DNA Technicians (Screeners trained to
extract/quant)
 Extracts passed on to DNA analysts
 Can employ personnel without DNA coursework


“Triage” – Determining samples to amplify
Scientific Data
◦ Sperm Results
◦ Male quantitation (Quantifiler Duo)
◦ Male: Female Ratio (Quantifiler Duo)

Case Scenario
◦
◦
◦
◦
◦
Single Suspect vs. Multiple Suspect
Consenting Partner
Minor Victim
Loss of Consciousness / Loss of Memory
Male Victim or Female Suspect
Category 1
Sperm Rating >1
Quant Duo >15 pg/µL
* 15% of samples
Category 4
Sperm Rating= 0
Quant Duo > 15 pg/µL
* 8% of samples
Category 2
Sperm Rating >1
Quant Duo =1-15 pg/µL
Category 3
Sperm Rating >1
Quant Duo =undetected
* 3% of samples
* 1% of samples
Category 5
Sperm Rating = 0
Quant Duo =1-15 pg/µL
Category 6
Sperm Rating = 0
Quant Duo = undetected
* 14% of samples
* 59% of samples






Official start date: December 3, 2012
1 Supervising Criminalist for case
management and admin reviews
9 DNA technicians
11 DNA analysts
Rotational duties – 2 DNA techs assigned to
non-diff extractions and quants per week
DNA analysts float into tech positions, as
needed
 Turnaround
time defined as:
◦ DATE REQUEST RECEIVED to DATE
REPORT ADMIN REVIEWED
 Average 63 days
 Range 2-90 days
250
Number of Kits In Progress Over Indicated Time
200
150
over 180 days
over 150 days
over 120 days
over 90 days
100
50
MSD
0

LAPD MSD process vs. LAPD “Old Way”
◦ Processing all kits with fewer personnel
than “old way” would require
 Increased reagent costs offset by salary
savings from increased productivity
◦ Faster turn-around
◦ Superior analytical results

How does MSD compare to other methods?
◦ Selective sampling (Fast Track Forensics – FTF)
used in Los Angeles for several years
 SART Nurse collects additional swabs & submits
directly to state lab for DNA extraction and
typing (no screening)
 Based on victim statements and physical findings
 FTF continued after implementation of LAPD
MSD
 Cases have been processed by both methods

Randomly selected 50 cases processed both
by selective sampling (FTF) & MSD
◦ Compared number of:
 swabs examined
 profiles developed
 CODIS uploads

Cases included
◦ 42% of victims reported loss of consciousness or
loss of memory


Average # of swabs screened per SAEK
◦ MSD = 7.6
◦ FTF = 0 (unscreened, all are DNA typed)
Average # of swabs DNA typed per SAEK
◦ MSD = 2.6
◦ FTF = 2.6
Unique CODIS Uploads (Out of 50 Cases)
30
25
25
20
15
11
10
5
0
MSD
FTF
CODIS Uploads

Will a detective recognize not all SAEK
profiles were detected and request
additional work?
◦ LAPD had assumed detectives would
request all SAEKs be tested that should be
tested.
 Of the 6,132 unexamined SAEKs identified in
the freezer audit:
 Over 400 were stranger rapes

Link cases
◦ Rapes in two different cities (without an arrest)
won’t be linked otherwise
◦ DDA’s will not file many cases with vulnerable
victims or consent issues
 Some criminals know this and deliberately target
vulnerable victims or develop “plausible” consent
 Without filing, no arrest and no entry into CODIS
◦ Multiple CODIS hits to the same offender can
encourage a DDA to file cases
 Multiple victims (even with credibility issues) can
corroborate each other

Gary Ridgway
◦ “Green River Killer”
◦ Convicted of killing 49 (likely over 70)
◦ Targeted prostitutes & runaways
◦ Ridgway “took advantage of (prostitute)
services regularly”

William Suff
◦ “Lake Elsinore Killer”/“Riverside Prostitute
Killer”
◦ Convicted of killing 12 (likely 22)
◦ Targeted prostitutes
◦ Suff escalated throughout his spree

Did they start with murder, or sexual assault?
◦ Was their first violent crime a homicide, or a sexual
assault?
 If the latter, did missed opportunities to link cases
allow them to victimize others & further hone their
“skills” to avoid detection & prosecution?
◦ Could their killing sprees have been cut short or
eliminated altogether if CODIS had linked them to
the reported sexual assaults of multiple vulnerable
victims?

Lab Director Doreen Hudson
◦ Had us examine other methods to back up our
consensus that we were doing things better

Supervising Criminalist Mike Mastrocovo
◦ Took GBI’s method and expanded it dramatically

Serology/DNA Unit
◦ Did a ton of case work, validations & innovations,
under intense media scrutiny & Department
pressure, to get us to where we are today
Jeff Thompson
323-415-8115
N2769@lapd.lacity.org