Checklist · Criminal

Challenging Forensic Evidence and Obtaining Laboratory Records: A Practical Checklist

18 U.S.C. § 3600

Type
Checklist
Jurisdiction
National
Date
2024-01-20
Topic
Criminal

A step-by-step checklist for challenging forensic evidence in a criminal case, ordered by what to do first. Section A is the intake triage that decides where the budget goes. Section B is the discovery demand, item by item, because the report is the conclusion and the bench notes are the evidence. Section C covers the confrontation objection and the notice-and-demand deadline that waives it more often than any ruling does. Section D covers the scope motion that outperforms the exclusion motion. Section E is discipline-specific, with the questions that have no good answer. Section F covers experts and funding. Section G covers trial preservation. Section H covers post-conviction testing and junk science relief.

Challenging Forensic Evidence and Obtaining Laboratory Records: A Practical Checklist

Criminal > Forensic Evidence and Crime Laboratories | Published 20 January 2024 - Updated 23 February 2025 | UpLaw - uplaw.us

Start here

Three rules organize this whole checklist:

  1. The report is the conclusion. The bench notes are the evidence. Get the file before deciding anything.
  2. Fight scope, not admissibility. The distance between "consistent with" and "identified" is where cases are won.
  3. Calendar the confrontation demand the day the report arrives. That right is lost on a calendar far more often than on the merits.

SECTION A — INTAKE TRIAGE

☐ Identify every forensic discipline in the case, and what each is being offered to prove ☐ Obtain every report; note the analyst by name for each ☐ Note the date of analysis — you will need the procedures in effect then, not today's ☐ Note whether the conclusion is categorical ("identified," "individualized," "source") or comparative ("consistent with," "cannot be excluded") ☐ Sort the disciplines: ☐ Quantitative foundation — single-source DNA, drug chemistry, toxicology ☐ Collapsed — bite mark, microscopic hair identification, comparative bullet lead, arson "indicators" ☐ Real but oversold — latent prints, firearms and toolmarks, shoe print, tire, handwriting, blood pattern ☐ Identify what was not tested, and who decided ☐ Calendar: notice-and-demand deadline · motions deadline · expert funding request · discovery deadline ☐ Decide the budget order — see Section F

SECTION B — THE DISCOVERY DEMAND

B1. The complete case file — not the report

☐ Bench notes and worksheets ☐ Photographs, including comparison images at working resolution ☐ Instrument output and raw electronic data — not printed summaries ☐ All draft reports and pre-review conclusions ☐ Technical and administrative review documentation — and whether the review was blind ☐ Chain of custody records; authentication material under Federal Rule of Evidence 901 ☐ Submission forms showing what was submitted versus what was analyzed ☐ Standard operating procedures in effect on the date of analysis ☐ Validation studies the laboratory relies on for this method ☐ Instrument calibration, maintenance, and malfunction logs ☐ Federal vehicle: Federal Rule of Criminal Procedure 16; state analogues vary and several are narrower

B2. The analyst — by name

☐ Proficiency test results, including failures ☐ Corrective action reports ☐ Internal audit findings and responses ☐ Accreditation assessments, deficiencies, and corrective actions ☐ Prior erroneous conclusions in other cases ☐ Contamination and quality-control incident records for the relevant period ☐ Disciplinary history and any misconduct finding ☐ Training records and qualifications ☐ Prior testimony transcripts in similar cases ⟵ the fastest way to learn what language they will use

📌 The laboratory is part of the prosecution team. What it knows is imputed to the State under Brady v. Maryland, 373 U.S. 83 and Giglio v. United States, 405 U.S. 150. Demand it in writing, in every case. Refused often; ordered sometimes; occasionally decisive.

B3. If refused

☐ Move to compel with a specific proffer of relevance — general requests are denied ☐ Request in camera review as a fallback ☐ Ask the court to order preservation of anything that might be destroyed on a retention schedule ☐ Renew after any development that changes materiality

SECTION C — CONFRONTATION

☐ First: find the notice-and-demand deadline. Most states have one, and missing it waives the objection regardless of the merits. ☐ File the demand for the analyst's appearance immediately on receiving the report ☐ Object to any laboratory report offered without the analyst who performed the work — Melendez-Diaz v. Massachusetts, 557 U.S. 305 ☐ Object to a surrogate analyst who did not perform or observe the testing — Bullcoming v. New Mexico, 564 U.S. 647 ☐ Object when an expert recites an absent analyst's findings as "basis" for an independent opinion — Smith v. Arizona, 602 U.S. 779 treats those statements as offered for their truth ☐ Ground the objection in Crawford v. Washington, 541 U.S. 36; note that Williams v. Illinois, 567 U.S. 50 produced no majority rationale and does not control ☐ Identify every analyst who touched the item — extraction, quantitation, amplification, interpretation may be four different people

SECTION D — THE SCOPE MOTION

D1. Frame it correctly

☐ Do not move to exclude unless the discipline has collapsed or the application is demonstrably unvalidated ☐ Move to limit the language — this succeeds far more often and frequently accomplishes more ☐ Cite Federal Rule of Evidence 702 as amended: the proponent must show, more likely than not, a reliable application of a reliable method ☐ Add Federal Rule of Evidence 403: a certainty claim the method cannot support is the paradigm of prejudice exceeding probative value ☐ Attack the basis under Federal Rule of Evidence 703 and demand underlying facts under Federal Rule of Evidence 705 ☐ Cite Kumho Tire Co. v. Carmichael, 526 U.S. 137 — gatekeeping reaches experience-based fields ☐ Cite General Electric Co. v. Joiner, 522 U.S. 136 — the analytical gap ☐ Cite the factors of Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, and press error rate and standards, which are the two the pattern disciplines cannot satisfy

D2. Ask for a specific order

The examiner may testify to shared characteristics, consistency, and inability to exclude. The examiner may not testify:

☐ to "identification" or "individualization" ☐ that the source is the defendant "to the exclusion of all others" ☐ to a zero or negligible error rate ☐ to a "reasonable degree of scientific certainty" ☐ to any numerical probability the discipline has not validated

☐ Request a hearing, and request advance disclosure of the validation literature and the procedure in effect on the analysis date ☐ Ask for the order in writing — an oral limitation is hard to enforce mid-testimony and hard to preserve

SECTION E — DISCIPLINE-SPECIFIC QUESTIONS

E1. Every discipline — the three with no good answer

☐ What study establishes the error rate for this method as you applied it here? ☐ What is the written standard for declaring a match, and where is it published? ☐ How would you know if you had been wrong?

E2. Latent fingerprints

☐ Is there a required number of corresponding points, and is it written down? ☐ Was the verification blind? ☐ Did you document the latent's features before viewing the known print? ☐ Latent quality: how many ridges, what distortion, what substrate? ☐ What false positive rate do published black-box studies report, and how does this latent compare to their samples? ☐ Do you claim a zero error rate? (Either answer helps.)

E3. Firearms and toolmarks

☐ What is the written standard for "sufficient agreement"? ☐ Is the judgment subjective? (It is.) ☐ Open-set versus closed-set validation studies — which apply here, and what were the results? ☐ How many known non-matching firearms did you compare? ☐ Has your laboratory's policy on source attribution changed recently? (Many have.)

E4. DNA

☐ How many contributors, and how determined? ☐ Template amount — was it below the stochastic threshold? ☐ Which peaks were called artifacts or stutter, and why? ☐ Did you know the suspect's profile before interpreting the mixture? ☐ Software name, version, parameters, and validation for this contributor number and template range ☐ What does the likelihood ratio mean in words? ☐ Is transfer or contamination excluded, and by what? ☐ Was this a database hit or a confirmatory comparison? (Different statistics.) ☐ Watch for the prosecutor's fallacy: the random match probability is not the probability of innocence

E5. Digital and cell site

☐ Sector coverage radius, and how determined — drive test or records? ☐ How many other towers could have served the location? ☐ Does the record show the device or the person? ☐ For extraction reports: what did you verify independently versus what did the tool assert? ☐ Tool validation and error characteristics for this data type

E6. Compare the report to the testimony

☐ Line by line. Conclusions grow between the written report and the stand, and the growth is the impeachment.

SECTION F — EXPERTS AND FUNDING

F1. Budget order — highest return first

☐ 1. The complete case file. Costs a motion. Everything else is guesswork without it. ☐ 2. A consulting expert to read the file. Frequently the highest-value expenditure in the case; the product is a list of where to look. ☐ 3. The scope motion. Attorney time only. ☐ 4. The analyst's proficiency and corrective action file. Costs a motion; occasionally decisive. ☐ 5. Reinterpretation of a DNA mixture. Real money, justified where "cannot exclude" is doing heavy work. ☐ 6. A testifying expert. Where the jury needs a competing voice, not just a competing cross. ☐ 7. Independent retesting. Most expensive; appropriate where the sample is adequate and the result could be dispositive.

F2. Moving for funds

☐ Be specific: name the expert, the discipline, the task, and why it matters to a contested issue ☐ Attach the report and quote the conclusion you intend to test ☐ Ask for a consulting expert first; a general request for "a DNA expert" is denied, a request to reinterpret a three-contributor mixture is granted far more often ☐ Request ex parte where the jurisdiction permits it, to avoid disclosing strategy ☐ Ask for authority to retain a separate testifying expert later if warranted

SECTION G — TRIAL

G1. Before the witness

☐ Confirm the written scope order is in the file and give a copy to the court reporter ☐ Prepare the impeachment file: the report, the bench notes, prior transcripts, the SOP in effect, proficiency records ☐ Prepare a demonstrative comparing the report language to the anticipated testimony

G2. During

☐ Object immediately if the examiner exceeds the scope order; ask for a curative instruction ☐ Object under Federal Rule of Evidence 703 if the basis includes an absent analyst's work, and add the confrontation objection under Smith v. Arizona, 602 U.S. 779 ☐ Cross on: no measured error rate · no written match standard · what the examiner knew about the case · whether verification was blind · what was not tested and who decided · presumptive versus confirmatory · that accreditation is laboratory-level and says nothing about this conclusion · that "reasonable degree of scientific certainty" is a legal phrase, not a scientific one

G3. Preservation

☐ Object with specificity and obtain a ruling ☐ Renew objections at trial even after a favorable pretrial ruling ☐ Make an offer of proof where your evidence is excluded ☐ Request findings on the Federal Rule of Evidence 702 analysis ☐ Remember review is deferential under Joiner, 522 U.S. 136 — the trial record is decisive. See Civil Appeals.

SECTION H — AFTER CONVICTION

H1. DNA testing

☐ Federal procedure: 18 U.S.C. § 3600; every state has an analogue with its own conditions and deadlines ☐ Confirm the evidence still exists — move for a preservation order before anything else ☐ Know that there is no freestanding constitutional right to testing — District Attorney's Office v. Osborne, 557 U.S. 52 ☐ If the state procedure itself is the obstacle, consider a civil rights action rather than habeas under 28 U.S.C. § 2254 — Skinner v. Switzer, 562 U.S. 521 ☐ Consider mitochondrial DNA where the original evidence was hair comparison

H2. The junk science writ

☐ Identify the discipline and the specific testimony given ☐ Assemble the change in scientific understanding, with sources ☐ Show materiality to the verdict ☐ Check the state's vehicle, its standard, and its deadlines — several have none, several are strict ☐ Screen simultaneously for Brady, 373 U.S. 83 and Giglio, 405 U.S. 150 violations that surfaced later — laboratory scandals frequently produce both ☐ See Post-Conviction Relief and Preparing and Filing a Post-Conviction Petition

H3. If a laboratory scandal is announced

☐ Determine whether the analyst touched this case — by name, across every step ☐ Request the notification list and the audit scope ☐ Move for preservation of all evidence and records ☐ Move for appointment of counsel where available ☐ Do not assume the state's own review captured your case; the scandal pattern is that nobody can say which results were affected

SECTION I — THE LABORATORY WORKFLOW AUDIT

Walk the case through the laboratory step by step and ask what you have for each. The report covers only the last two.

# Step What to obtain What can go wrong
1 Collection Scene log, photographs, collection notes, officer reports Selection under time pressure by someone with a theory; contamination at the scene
2 Packaging / chain Chain documents, evidence receipts, storage records Gaps go to weight, not admissibility — so they rarely exclude anything
3 Triage Submission forms; what was submitted vs. analyzed Invisible in the report; untested items are untested facts
4 Screening Screening notes and results Presumptive results reported as identifications
5 Confirmation Instrument logs, calibration, maintenance, raw output Malfunction, calibration lapse, misread output
6 Interpretation Bench notes, worksheets, draft conclusions The subjective step; where bias operates
7 Review Review documentation Meaningless if the reviewer knew the conclusion — ask whether it was blind
8 Reporting SOP in effect on the analysis date Categorical overstatement enters here
9 Testimony Prior transcripts by this analyst The conclusion grows between report and stand

☐ For each row, note what you have, what you requested, and what was refused ☐ Refusals are the map: a laboratory that will not produce draft conclusions or review documentation is telling you where to look

SECTION J — COGNITIVE BIAS AUDIT

Nobody has to lie for this to go wrong. Most comparison is a subjective judgment by a person who knows what answer the case wants.

Ask what the examiner knew before beginning:

☐ Did you know a suspect had confessed or made statements? ☐ Did you know the suspect's criminal history? ☐ Did you know an eyewitness had identified someone? ☐ Did you know whether the suspect was in custody? ☐ Did you speak with the investigating officer, and what was said? ☐ Were you given one reference sample alongside the questioned sample, or an array?

Ask what controls the laboratory has implemented:

☐ Linear sequential unmasking — features of the questioned sample documented before viewing the reference? ☐ Blind verification — did the verifier know your conclusion? ☐ Case manager filtering irrelevant context? ☐ Blind proficiency testing embedded in ordinary casework, or announced tests?

📌 Few laboratories have implemented all of these, and those that implemented some frequently cannot say which. Each "no" is a cross-examination line that requires no expert to deliver.

SECTION K — THE ONE-PAGE VERSION

☐ 1. Identify every discipline, every analyst by name, and every date of analysis. ☐ 2. Calendar the notice-and-demand deadline the day the report arrives. ☐ 3. Demand the complete case file — bench notes, raw data, drafts, SOP in effect — not the report. ☐ 4. Demand the analyst's proficiency and corrective action file by name, under Brady, 373 U.S. 83 and Giglio, 405 U.S. 150. ☐ 5. Move for a consulting expert with a specific, named task. ☐ 6. File the scope motion, not the exclusion motion, under Federal Rule of Evidence 702 and Federal Rule of Evidence 403, citing Daubert, 509 U.S. 579 and Kumho Tire, 526 U.S. 137. ☐ 7. Get the limiting order in writing. ☐ 8. Object to any report without its analyst — Melendez-Diaz, 557 U.S. 305, Bullcoming, 564 U.S. 647, Smith v. Arizona, 602 U.S. 779. ☐ 9. Cross on error rate, written standards, what the examiner knew, and blind verification. ☐ 10. Compare the report to the testimony, sentence by sentence. ☐ 11. Preserve everything; review is deferential and the trial record is the case. ☐ 12. After conviction: preservation order first, then testing under 18 U.S.C. § 3600 or the state analogue, then the junk science vehicle.

SECTION L — WHAT TO EXPLAIN TO THE CLIENT

Forensic evidence persuades clients as much as it persuades juries, and a client who believes the case is over stops helping. Explain these five things plainly.

☐ "Match" usually is not a defined term. In most comparison disciplines there is no written standard for what counts as one. That is not a technicality; it is the whole issue.

☐ "Cannot be excluded" is weak. In a complex DNA mixture, large numbers of people cannot be excluded either.

☐ A random match probability is not the chance you are innocent. One in a billion describes how often an unrelated stranger would match. It says nothing on its own about everything else in the case.

☐ DNA on an object does not prove you touched it, or when. Trace amounts transfer between people, objects, vehicles, and laboratory surfaces.

☐ What was not tested matters. Untested items are untested facts, and someone made that decision.

☐ The realistic goal is usually to limit what the examiner may say, not to keep them off the stand. That is not a lesser outcome; a jury hears "consistent with" very differently from "identified."

SECTION M — DEADLINES TO CALENDAR ON DAY ONE

Deadline Source Consequence of missing
Notice-and-demand for the analyst State statute Confrontation objection waived — the most common loss in this field
Expert funding motion Local rule / statute No expert, no reinterpretation
Discovery motion deadline Scheduling order No bench notes
Motions in limine deadline Scheduling order No scope order
Federal Rule of Criminal Procedure 16 reciprocal disclosure Rule Preclusion of your own expert
Evidence retention schedule Laboratory policy Records destroyed before you ask
Post-conviction testing petition 18 U.S.C. § 3600 / state analogue Testing unavailable
Junk science writ State statute Relief unavailable

☐ Send a preservation letter immediately covering the physical evidence, the electronic data, the bench notes, the instrument logs, and the analyst's records. Retention schedules run whether or not anyone has asked.

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