Assessing dimensions of competency to stand trial: construct validation of the ECST-R

Assessment. 2003 Dec;10(4):344-51. doi: 10.1177/1073191103259007.


Four decades of forensic research have left unanswered a fundamental issue regarding the best conceptualization of competency to stand trial vis-à-vis the Dusky standard. The current study investigated three competing models (discrete abilities, domains, and cognitive complexity) on combined data (N = 411) from six forensic and correctional samples. Using the Evaluation of Competency to Stand Trial-Revised (ECST-R), items representative of the Dusky prongs were used to test the three models via maximum-likelihood confirmatory factor analyses (CFA). Of the three, only the discrete abilities model evidenced a good fit, indicating that competency to stand trial should consider separately each defendant's factual understanding of the proceedings, rational understanding of the proceedings, and ability to consult with counsel. ECST-R competency scales, based on the current CFA, have excellent alphas (.83 to .89) and interrater reliabilities (.97 to .98).

Publication types

  • Legal Case
  • Validation Study

MeSH terms

  • Adult
  • Female
  • Forensic Psychiatry / methods*
  • Humans
  • Interview, Psychological / methods*
  • Jurisprudence
  • Male
  • Mental Competency / classification*
  • Mental Competency / legislation & jurisprudence
  • Models, Psychological*
  • Psychiatric Status Rating Scales
  • Psychometrics
  • Supreme Court Decisions
  • United States