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Defense expert testimony

Smith v. United States

Updated Nov 12, 2026

In brief

Where it stands
Dismissed

Petition denied.

What it’s about
Terrill Smith's petition asks whether his trial lawyer had to investigate expert testimony on a key issue after the government planned to present its own expert, and whether failing to do so could have affected the verdict.
Who it affects
The Ninth Circuit's decision remains in place in Smith's case, but the Supreme Court did not decide whether his lawyer's failure to investigate expert testimony affected the trial.

Summary: written with AI from the case record.

Illustration for Terrill Smith, Petitioner v. United States
Conceptual illustration · AI-generated

What it's about

The dispute focuses on whether defense lawyers must investigate expert evidence when the government plans to use specialized testimony on an important issue.

Question presented

1. Whether, after Harrington v. Richter, 562 U.S. 86 (2011), trial counsel still has a duty to investigate whether expert testimony could significantly bolster the defense regarding what is obviously a critical issue in a criminal case when it is clear the government will present specialized testimony on the issue. 2. Whether a defendant is prejudiced by the failure to investigate potential expert testimony about a critical issue in the case if a reasonable juror could decline to convict after hearing the expert testimony proffered in postconviction proceedings.

Documents

1

Docket activity

7
  • New analysis added

    Nov 12, 2026 · Court records

  • AI analysis generated: Case Briefing

    Nov 12, 2026 · Generated

  • AI analysis generated: Decision Record

    Nov 12, 2026 · Generated

  • New analysis added

    Nov 11, 2026 · Court records

  • Case data updated: summary, question_presented, generation_metadata

    Nov 11, 2026 · Court records

Show 2 more
  • Case data updated: question_presented, extraction_metadata

    Nov 11, 2026 · Court records

  • Brief added: Petition

    Aug 28, 2026 · Court records

Sources

Primary materials plus reporting. Best-effort analysis: this explainer relies on a mix of primary materials and trusted secondary sources. Official filings and opinions remain authoritative.

Checked Nov 12, 2026Methodology

Court records and filings

Reporting and analysis