People v. Dupree, 2018 IL 122307

Torrence Dupree was convicted (jury, Lake County) of two counts each of armed robbery and aggravated robbery based principally on identifications by Steven Nowell and Kiernan Collins; no physical evidence tied Dupree to the crime.
Matthew Morrison was the victim and gave three written statements to police: he described the robber as "tall" (about 6'–6'3") and twice did not identify Dupree from photo lineups, selecting another person instead.
At trial Morrison did not testify; the defense called only Dupree's cousin (height testimony). The State elicited jail calls and Nowell's testimony that implicated Dupree; Nowell had pleaded guilty to reduced charges in exchange for testifying.
Dupree filed a postconviction petition claiming, among other things, ineffective assistance of trial counsel for failing to call Morrison to present his prior statements; Dupree attached Morrison's police statements and reports but not an affidavit from Morrison.
The circuit court dismissed at the second stage for failure to show prejudice; the appellate court affirmed but based its decision solely on Dupree's failure to attach Morrison's affidavit, holding that such an affidavit is required.
The Illinois Supreme Court granted review, held that an affidavit is not categorically required where other records already in the record supply the substance of the proposed witness's expected testimony, but affirmed dismissal on the merits because Dupree failed to make the required Strickland showing.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether absence of an affidavit from a proposed witness is fatal to an ineffective-assistance claim at second-stage postconviction review	Appellate court (and State) argued an affidavit from the proposed witness is required to evaluate the claim	Dupree argued Morrison's written statements and police reports (already in the record) adequately supported the claim without an affidavit	Court: No bright-line affidavit requirement; records or other evidence can suffice when they already show what the witness would say (affidavit not per se fatal)
Whether defense counsel was ineffective for failing to call Morrison	Dupree: Morrison's statements would have undercut identifications (height discrepancy, selection of another photo) and likely changed the verdict	State: Morrison's statements were cumulative or could have reinforced Nowell's role; calling him risked harmful evidence; counsel could reasonably decline for strategy	Court: Even assuming some deficiency, Dupree failed Strickland prejudice prong—Morrison's statements were cumulative or of limited value given Nowell’s strong ID and corroborating evidence; dismissal affirmed

Strickland v. Washington, 466 U.S. 668 (1984) (two-prong standard for ineffective assistance: deficient performance and prejudice)
People v. Enis, 194 Ill. 2d 361 (2000) (addressing requirements for supporting evidence for failure-to-call-witness claims)
People v. Johnson, 183 Ill. 2d 176 (1998) (affidavit requirement and analysis of cumulative testimony)
People v. Guest, 166 Ill. 2d 381 (1995) (need for affidavits to show proposed witnesses' favorable testimony)
People v. Thompkins, 161 Ill. 2d 148 (1994) (assessment of claims that counsel failed to investigate or call witnesses)
People v. Albanese, 104 Ill. 2d 504 (1984) (Illinois adoption of Strickland standard)