State v. Costell, 2021 Ohio 4363

Background:

Victim Debra Costell, a bedridden paraplegic, was found dead on Sept. 25, 2013; autopsy/toxicology showed toxic/ lethal levels of sertraline and tramadol.
Investigation: Jon Costell (husband/caregiver) was the only person with Debra shortly before death and provided her medication; charged with aggravated murder, failing to provide for a functionally impaired person, domestic violence, and involuntary manslaughter; convicted by jury and sentenced.
On direct appeal Costell raised multiple ineffective-assistance claims; conviction affirmed.
Costell filed a timely postconviction petition attaching two new expert reports opining Debra’s death resulted from her medical conditions (not the drug combination) and claiming trial counsel was ineffective for failing to (a) file a Daubert challenge, (b) consult experts, (c) investigate medical evidence, and (d) present exculpatory experts.
Trial court denied the petition as without merit (and stated res judicata applied); Costell appealed.
Appellate court held the petition was timely and not barred by res judicata because the reports were dehors the record, but affirmed denial on the merits: reports did not show counsel’s performance was deficient or prejudicial; any trial-court reference to res judicata was harmless.

Issues:

Issue	Plaintiff's Argument (State)	Defendant's Argument (Costell)	Held
Res judicata — does it bar the petition?	Petition barred by res judicata	Two post-trial expert reports are evidence dehors the record so res judicata does not bar review	Reports are dehors the record, so res judicata did not bar consideration; trial court nonetheless considered merits and any res judicata statement was harmless
Failure to file Daubert challenge	Daubert would not have succeeded; reports do not show state experts’ methods inadmissible	Counsel was ineffective for not moving to exclude state experts under Daubert	Reports failed to show the State experts used untested/unsupported methods or that a Daubert motion would have succeeded; no deficient performance shown
Failure to consult appropriate experts	No requirement to consult multiple experts; tactical choice	Counsel failed to consult experts who would support alternative cause of death	Decision whether and whom to consult is tactical; no showing counsel’s performance was unreasonable
Failure to investigate medical evidence / not calling experts	Defense vigorously cross‑examined state experts; record silent does not prove failure	Counsel did not investigate or retain experts who would show alternate cause of death	Silent record cannot establish failure to investigate; cross‑examination was robust; no deficient performance or prejudice shown
Failure to present exculpatory expert testimony	Postconviction experts offer alternative/supplementary theories only; not enough to show counsel deficient	Counsel unreasonably failed to call the two postconviction experts whose reports exonerate Costell	Post hoc expert opinions merely supplement trial theory; alternate theories in postconviction proceedings do not establish ineffective assistance; no prejudice established

Key Cases Cited

Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (U.S. 1993) (federal gatekeeper standard for expert admissibility)
Strickland v. Washington, 466 U.S. 668 (U.S. 1984) (two‑part test for ineffective assistance of counsel)
State v. Nemeth, 82 Ohio St.3d 202 (Ohio 1998) (Ohio adoption of Daubert factors under Evid.R.702)
State v. Perry, 10 Ohio St.2d 175 (Ohio 1967) (res judicata bars issues raised or that could have been raised on direct appeal)
State v. Cole, 2 Ohio St.3d 112 (Ohio 1982) (res judicata as basis to dismiss R.C. 2953.21 petition)
State v. Jackson, 64 Ohio St.2d 107 (Ohio 1980) (standards for proving ineffective assistance in postconviction petitions)
State v. Nicholas, 66 Ohio St.3d 431 (Ohio 1993) (failure to call an expert can be sound trial strategy)
State v. Steffen, 70 Ohio St.3d 399 (Ohio 1994) (issues raised or that could have been raised on direct appeal are barred)
State v. Were, 118 Ohio St.3d 448 (Ohio 2008) (cannot infer failure to investigate from a silent record)