📄 Lab Proficiency Quality Control
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Lab Proficiency Quality Control

48 items · 48 documentary · 29 with detail pages

Barry Scheck and Dr. John Gerdes presented proficiency tests, contamination charts, and validation studies from the LAPD Crime Lab to establish systematic failures in DNA analysis. Charts documented contamination rates exceeding 30% in mid-1994; proficiency tests revealed errors by analyst Collin Yamauchi; validation studies exposed protocol violations. These exhibits directly challenged the reliability of LAPD's DNA evidence—the prosecution's forensic cornerstone.

Detailed entries (29)

LAPD July 1993 Proficiency Test Error Slides
📄 Documentary

Slides documenting LAPD PCR proficiency test results from July 14-15, 1993, showing contamination in negative controls and incorrect DNA typing attributed to analyst Erin Riley; Defense 1314 and sub-exhibits 1314-A through 1314-G.

Defense 1314Defense 1314-ADefense 1314-BDefense 1314-CDefense 1314-DDefense 1314-E +3
2 procs · 2 people
Yamauchi Validation Hybridization Records
📄 Documentary

DNA hybridization records filled out by Collin Yamauchi documenting his actual PCR typing results on 11 mock vaginal swab validation samples; Defense 1181-C through 1181-E. Gerdes identified one entry as an incorrect typing of a sample as 1.2, 4 instead of the correct 1.2, 1.3.

Defense 1181-CDefense 1181-DDefense 1181-EDefense 1181-C, D, E
2 procs · 3 people
Gerdes Mistyping Consequence Slides
📄 Documentary

Slides illustrating the correct typing, LAPD's incorrect typing, and the resulting wrongful inclusions and exclusions arising from the mock validation mistyping; Defense 1313-A through 1313-C.

Defense 1313-ADefense 1313-BDefense 1313-CDefense 1313-A through 1313-C
1 proc · 2 people
Gerdes Chart — LAPD Run Contamination by Month
📄 Documentary

Chart showing the percentage of LAPD PCR runs with contamination by month from May 1993 through August 1994, used by Gerdes to document contamination patterns in the LAPD laboratory; Defense 1295.

Defense 1295Defendant's 1295
4 procs · 3 people
LAPD Validation Run No. 37 — Erin Riley, Sept. 21, 1993
📄 Documentary

Hybridization record and raw data from the LAPD September 21, 1993 mock vaginal swab validation study run no. 37, analyst Erin Riley confirmed by Collin Yamauchi; cited by Gerdes as the fourth of five LAPD typing errors.

People's 562Prosecution's 562
2 procs · 3 people
Cellmark 1988 CACLD Proficiency Test and Report
📄 Documentary

The 1988 California Association of Crime Laboratory Directors proficiency test administered to Cellmark (49 samples, 1 false positive attributed to inadvertent cross-contamination that Cellmark did not detect itself). Defense 1154 is the six-page CACLD report on this test, including a letter from CACLD to Cellmark regarding blind trial results.

Defense 1154
4 procs · 3 people
Gerdes Chart — LAPD Runs and Strips May–July 1994
📄 Documentary

Chart showing the percentage of LAPD PCR runs and strips with contamination and/or artifacts from May through July 1994, with monthly bars approximating 33%, 31%, and 17%; Defense 1297.

Defense 1297
4 procs · 3 people
LAPD PCR Validation Training Record
📄 Documentary

LAPD PCR method validation training record stating that every validation sample either gave the expected typing result or no typing result, introduced as Defense 1181-A. Gerdes contradicted this claim by pointing to Yamauchi's actual hybridization records.

Defense 1181-A
3 procs · 3 people
CACLD Blind Trial Proficiency Report (Defense 1183)
📄 Documentary

Nine-page California Association of Crime Laboratory Directors report on blind proficiency trial results, introduced and cross-referenced during testimony about LAPD and Cellmark testing practices.

Defense 1183
2 procs · 2 people
Four Types of Proficiency Tests Diagram
📄 Documentary

Hand-drawn diagram created during Dr. Cotton's testimony categorizing proficiency tests into four types (open/blind, internal/external), introduced as Defense 1153.

Defense 1153
2 procs · 2 people
Gerdes Chart — LAPD Contamination by Control Type
📄 Documentary

Chart showing the percentage of contamination by extraction control type at the LAPD lab from May through July 1994, showing 10 of 25 extraction controls contaminated; Defense 1298.

Defense 1298
2 procs · 2 people
Gerdes Chart — LAPD Strip Contamination by Month
📄 Documentary

Chart summarizing the percentage of LAPD PCR strips showing contamination and/or artifacts by month from May 1993 through August 1994; Defense 1287.

Defense 1287
2 procs · 2 people
LAPD Validation Standards and Mock Swab Code Sheet
📄 Documentary

LAPD validation standards list and code sheet identifying the individuals and correct expected typing results used in mock vaginal swab validation tests; Defense 1181-B.

Defense 1181-B
2 procs · 3 people
Yamauchi September 9, 1993 Validation Test Data
📄 Documentary

Raw data and typing report from Collin Yamauchi's September 9, 1993 mock vaginal swab validation study, showing a 1.2, 4 result for the sperm fraction of sample no. 1, challenged as an incorrect typing; Prosecution's 561.

Prosecution's 561
2 procs · 3 people
Yamauchi Validation Study — Defense 1181 Packet
📄 Documentary

LAPD internal report on Yamauchi's mock vaginal swab validation study results, stating he correctly typed every sample, together with the physical mock vaginal swab sample used in the testing; collectively referenced as Defense 1181.

Defense 1181
2 procs · 3 people
CAP External Proficiency Test Hybridization Record
📄 Documentary

Hybridization record from a College of American Pathologists external proficiency test, listing Collin Yamauchi as analyst and Erin Reilly as confirming analyst, used to demonstrate that LAPD did not use blind testing procedures; Defense 1182.

Defense 1182
1 proc · 2 people
Cellmark Report to CACLD on 1988 Proficiency Test
📄 Documentary

Three-page Cellmark Diagnostics report submitted to the California Association of Crime Laboratory Directors on the 1988 proficiency test results.

Defense 1155
1 proc · 2 people
Gerdes Chart — LAPD Contamination Analysis
📄 Documentary

Gerdes contamination analysis chart introduced during discussion of a specific strip series; Defense 1288.

Defense 1288
1 proc · 2 people
Gerdes Cross-Contamination Factors Slide Set
📄 Documentary

Slide set titled 'Cross-contamination factors,' previously marked as Defense 1149-A, referenced and displayed during Gerdes' testimony.

Defense 1149-A
1 proc · 2 people
LAPD DNA Extraction Chelex Bottle
📄 Documentary

Chelex bottle used in LAPD DNA extraction, lot no. 5, representing a six-month supply used without aliquoting; Defense 1306.

Defense 1306
1 proc · 2 people
LAPD Hybridization Record No. 15
📄 Documentary

LAPD hybridization record no. 15, related to the first LAPD PCR typing error identified by Gerdes; People's 558.

People's 558
1 proc · 2 people
LAPD PCR Proficiency Test — First Run (Defense 1172-A)
📄 Documentary

First run of an LAPD PCR proficiency test showing one hint and one trace in results, introduced during cross-examination of Montgomery.

Defense 1172-A
1 proc · 2 people
LAPD PCR Proficiency Test — Second Run (Defense 1172-B)
📄 Documentary

Second run of an LAPD PCR proficiency test showing three traces in evidence samples, used by Blasier to highlight that traces appeared but the test was not re-run.

Defense 1172-B
1 proc · 2 people
LAPD TE Buffer Bottle (Yamauchi Workstation)
📄 Documentary

TE buffer bottle at Collin Yamauchi's workstation, dated 5-25-93 but photographed January 18, 1995, representing another reagent used without aliquoting; Defense 1307.

Defense 1307
1 proc · 2 people
Mock Vaginal Swab Validation Code Sheet
📄 Documentary

Code sheet for the mock vaginal swab validation exercise indicating the correct expected typing results for each sample.

2 14-6
1 proc · 2 people
Gerdes LAPD Lab Contamination Study Report
📄 Documentary

Dr. John Gerdes' study and formal report on contamination at the LAPD crime laboratory, based on LAPD's own data. The report was still in progress during early pretrial motions and was eventually received by the prosecution as a four-page formal expert report.

3 procs · 2 people
ASCLAD Laboratory Accreditation Standards
📄 Documentary

American Society of Crime Laboratory Directors (ASCLAD) accreditation standards and guidelines, discussed to establish whether LAPD met accreditation requirements, including standards governing pen vs. pencil documentation in laboratory notes.

2 procs · 3 people
CACLD 1988–1989 Proficiency Study False Positive References
📄 Documentary

General references to CACLD external proficiency study reports from 1988-1989 documenting alleged false positives at both Cellmark and Forensic Sciences Associates, used to challenge overall lab quality controls.

2 procs · 3 people
DOJ Quality Control Sample 816
📄 Documentary

DOJ quality control sample 816, which should have typed as 1.2/1.2 but showed hints of 1.1 and 1.3 alleles, used to challenge LAPD and DOJ quality control procedures.

2 procs · 3 people

Additional references (19)

Brief references from transcripts that don't warrant an individual page. Each has a single source or is mentioned only in passing.

  • 1993 EDTA Bloodstain Swatches (Martz Validation) — 1993 laboratory bloodstain swatches used by FBI chemist Roger Martz as validation samples to demonstrate that EDTA remains detectable in aged preserved blood.
  • Blood Standard No. 1 — Positive Control — Blood standard no. 1, used as a positive control in LAPD PCR quality control procedures.
  • California Association Open Proficiency Test Data — Open proficiency test data from Cellmark, LAPD, and DOJ laboratories distributed by the California Association of Crime Lab Directors, discussed by Dr. Speed to evaluate whether labs used degraded or case-representative samples in proficiency testing.
  • Cellmark 1989 CACLD Proficiency Test — The 1989 CACLD proficiency test administered to Cellmark (50 samples, 1 false positive), challenged as a second data point for lab error rate calculation.
  • Cellmark Proficiency Test Documentation 1990–1993 — Proficiency test documentation covering 104 tests and 466 samples conducted by Cellmark from 1990 to 1993, cited from Dr. Cotton's notes during cross-examination.
  • Cloth Control — Negative Control — Cloth control used as a negative control in LAPD PCR quality control procedures.
  • CTS External Proficiency Test Subscription — LAPD subscription to CTS (Collaborative Testing Services) external proficiency testing, discussed to establish that the program did not employ blind testing procedures.
  • DNA Proficiency Test Photographs — Photographs of DNA proficiency test results, for which the prosecution agreed to provide improved copies following a defense request.
  • DOJ Quality Control Samples 816 and 877 — DOJ quality control samples 816 and 877, both run in the same batches as case items 31 and 52 and both showing hint or trace of the 1.3 allele, cited by Gerdes as evidence of control failure.
  • Gerdes Contamination Chart with Faint-Dot Annotations — Gerdes' contamination chart with handwritten notations identifying faint dots and questionable results, discussed during testimony at criminal day 129 without a formal exhibit number assigned.
  • Gerdes Draft Analysis of LAPD Validation Studies — Interim or draft analysis of LAPD validation studies prepared by Dr. Gerdes prior to his January laboratory visit, referenced in notes as 'See analysis discussion for detailed explanation'; its disclosure status was disputed at trial.
  • Gerdes Federal Grant Proposal — Dr. Gerdes' federal grant proposal, page 31, containing the phrase 'most of our testing could be described as home-brewed as opposed to commercial kits,' quoted by Clarke on cross-examination to impeach Gerdes' testimony about kit usage at LAPD.
  • Item 52 — Gerdes Cross-Contamination Assessment — Item 52 stain that Gerdes assessed as a possible cross-contamination result in the LAPD laboratory.
  • LAPD PCR Test Kit Lot with Contamination — PCR test kit lot identified as having a contamination issue at the LAPD laboratory; Matheson clarified that the contamination was detected by internal controls and was a kit-specific problem rather than a lab-wide failure.
  • LAPD Proficiency Testing Records (Discovery) — Proficiency testing records obtained through discovery and reviewed by witness Montgomery on the stand, confirming that four of five proficiency tests involved the D1S80 locus.
  • LAPD Validation Specimens and CTS/CAP Proficiency Materials — LAPD validation specimens and CTS/CAP proficiency test materials, criticized by Gerdes as unrepresentative of case-condition degraded samples.
  • NRC Report on Laboratory Error Rates — National Research Council (NRC) report, pages 88-89 on laboratory error rates and page 171 glossary on proficiency testing definitions, offered by defense to challenge LAPD DNA methodology; sustained as hearsay because Sims did not rely on it in forming his opinions.
  • QA/QC Document Shown to Mazzola — Document labeled 'Quality assurance and quality control' shown to analyst Mazzola to refresh her recollection; she stated the document did not look familiar to her.
  • Substrate Control Samples — Clean with No Visible Dirt — Substrate controls described as clean with no visible dirt, which Gerdes argued suggested improper collection technique or falsified documentation at the LAPD laboratory.
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