State v. Fernando V., 170 Conn. App. 44

Defendant Fernando V. convicted after jury trial of two counts of second‑degree sexual assault and two counts of risk of injury to a child based principally on the complainant B’s testimony; no physical or third‑party corroboration existed.
State introduced testimony from a child‑sexual‑abuse/delayed‑disclosure expert that victims often show behavioral changes (e.g., withdrawal), and B’s mother testified B had become more withdrawn and stayed in her room.
Defense sought to call B’s longtime boyfriend (P) to testify that over four years he observed no pronounced behavioral changes in B and that the defendant never forbade or interfered with P’s dating or contacts with B.
Trial court excused the jury and excluded P’s testimony sua sponte, ruling it collateral, not probative, and likely to confuse the jury; the defense proffer was placed on the record.
On appeal the defendant argued exclusion was an abuse of discretion and not harmless because the prosecution’s case turned on credibility and the expert/mother evidence opened the door to lay testimony rebutting alleged behavioral indicators of abuse.
Appellate court concluded the trial court abused its discretion by excluding P’s testimony (both as direct evidence and, in part, impeachment) and that the error was not harmless; reversed and remanded for a new trial.

Issue	State's Argument	Defendant's Argument	Held
Admissibility of boyfriend P’s testimony	Offered only as extrinsic impeachment; inconsistent with record and collateral	P’s lay observations were direct evidence of B’s behavior and, alternatively, admissible impeachment of mother/B	Court abused discretion in excluding P’s testimony; it was relevant and not merely collateral
Whether defendant opened door by eliciting behavioral evidence	State argued expert and mother testimony did not create contradiction warranting extrinsic evidence	Defense argued state’s expert and mother made behavioral characteristics an issue, permitting defense lay rebuttal	Admission was proper because state introduced behavior evidence and defense entitled to contradictory lay evidence
Collateral‑matter doctrine as bar to extrinsic impeachment	State: contradiction was collateral and cumulative; extrinsic impeachment not allowed	Defense: testimony contradicted material credibility evidence (withdrawal, interference with boyfriends)	Trial court misapplied collateral rule; testimony bore on material issue of credibility
Harmless error analysis	Exclusion harmless because jury already heard about B’s boyfriends, grades, activities	Exclusion prejudicial because case was credibility‑driven and expert framing made behavioral evidence central	Error was not harmless; reversal and new trial ordered

State v. Alex B., 150 Conn. App. 584 (appellate standard for evidentiary rulings)
State v. McClendon, 199 Conn. 5 (general admissibility of relevant evidence)
State v. Warren, 14 Conn. App. 688 (witness may be contradicted by other witness testimony)
State v. Smith, 49 Conn. App. 252 (extrinsic impeachment and collateral‑matter rule)
State v. Carbone, 172 Conn. 242 (extrinsic evidence not allowed to impeach collateral matters)
State v. Polynice, 164 Conn. App. 390 (appellate review limited to theories raised at trial)
State v. Eleck, 314 Conn. 123 (harmless‑error standard for evidentiary rulings)
State v. Wilson, 308 Conn. 412 (reversible error when excluded evidence may substantially influence jury)
State v. Genotti, 220 Conn. 796 (avoiding unnecessary constitutional rulings)
State v. Little, 138 Conn. App. 106 (caution about excluding overlapping/cumulative evidence)