State of Arizona v. Dustin Gill, 391 P.3d 1193

In 2013 Dustin Gill was charged with felony marijuana possession; the State later offered TASC diversion (deferred prosecution) at a settlement conference on Sept. 3, 2014.
At the conference the court, prosecutor, and defense counsel repeatedly explained that participation in TASC was a deferred prosecution (no guilty plea required); Gill opted into TASC and completed a TASC "Statement of Facts" admitting possession and initialed a warning that the statement could be used against him if he failed the program.
The State later resumed prosecution after Gill failed to complete TASC; at trial the State used Gill’s TASC statement and he was convicted after a bench trial.
Gill moved to suppress the TASC statements as inadmissible under Ariz. R. Evid. 410(a)(4) (statements made during plea discussions), arguing (1) the TASC statement was made in furtherance of plea discussions, (2) the TASC representative was the prosecutor’s agent, and (3) any Rule 410 protection was not knowingly waived.
The trial court denied suppression; the court of appeals rejected Gill’s arguments and affirmed; the Arizona Supreme Court granted review to decide whether Rule 410(a)(4) applies to deferred prosecution agreements and whether Gill knowingly waived Rule 410.

Issue	Gill’s Argument	State’s Argument	Held
Does Ariz. R. Evid. 410(a)(4) bar admission of statements made in connection with deferred prosecution (TASC)?	Statements to TASC were made in furtherance of plea discussions and thus protected.	Rule 410 applies only to plea discussions (guilty/no contest pleas); deferred prosecution/diversion is not a plea.	Deferred prosecution discussions are not plea discussions under Rule 410; Rule 410 does not bar these statements.
Was the TASC representative an agent of the prosecutor for purposes of Rule 410?	The TASC rep acted on behalf of the county attorney (form bore county attorney name; admission required), so Rule 410 should extend to that agent.	Even if Rule 410 reaches agents, the TASC rep here was not acting as an agent to negotiate a plea—only to effect the deferred prosecution.	Rule 410 extends to prosecutor agents generally, but the TASC rep was not the prosecutor’s agent for plea negotiation, so Rule 410 did not apply.
Did Gill knowingly waive Rule 410 protections?	Waiver was ineffective because the waiver did not specifically reference Rule 410.	Waiver need not name the rule; it must be knowing and voluntary with awareness of consequences.	Waiver was knowing: Gill was warned statements could be used if he failed TASC, initialed and signed the form with counsel present; explicit reference to Rule 410 not required.

State v. Tucker, 215 Ariz. 298 (review standard for evidence admission)
State v. Romero, 239 Ariz. 6 (interpretation of evidentiary rules reviewed de novo)
Espinoza v. Martin, 182 Ariz. 145 (definition of plea negotiations under Arizona rules)
State v. Campoy, 220 Ariz. 539 (Rule 410 protection extended to communications similar to plea contexts)
United States v. Mezzanatto, 513 U.S. 196 (Rule 410 waiver enforceable unless involuntary or unknowingly made)