Background
Jeffrey Aschenbrenner’s ex-partner M.M. decided to move out of their shared home with her father G.M.’s assistance. While retrieving two vehicles—a Mercedes titled in Aschenbrenner’s name and an Audi M.M. had purchased—the two were confronted by Aschenbrenner near his home. Gunshots were fired at close range. M.M. was struck in the stomach during a chase and died from her injuries. G.M. narrowly escaped harm. Ballistic evidence showed the bullet that killed M.M. came from the same gun used in the initial confrontation.
Aschenbrenner was charged with two counts of first degree murder for M.M.’s death and attempted first degree murder for the shots fired at G.M. His primary defense was that the prosecution failed to prove he was the shooter. At trial, the jury rejected the deliberation theory but convicted him of first degree extreme indifference murder and attempted second degree murder as a lesser included offense. He received the mandatory sentence of life imprisonment without parole.
The Court’s Holding
The Colorado Court of Appeals affirmed all convictions and the mandatory life sentence. The court rejected Aschenbrenner’s argument that evidence of M.M.’s drug possession should have been admitted, finding it irrelevant without an identified alternate suspect and unduly prejudicial. The court also rejected prosecutorial misconduct claims, holding that the prosecutor’s comments about the lack of evidence supporting an alternate-suspect theory did not improperly shift the burden of proof, constitute a comment on Aschenbrenner’s failure to testify, or create plain error regarding the mental state for attempted extreme indifference murder (the prosecution’s misstatement was harmless because he was convicted of a lesser offense).
The court further held that Aschenbrenner was not entitled to a jury instruction on defense of property. The defense applies only to prevent an attempted theft, not to recover property already taken. Here, the vehicles had been moved away from Aschenbrenner’s property before he confronted M.M. and G.M., so any alleged theft had been completed. Finally, the court upheld the mandatory LWOP sentence as constitutionally proportionate, noting that first degree murder is a per se grave offense to which LWOP is a constitutionally appropriate response.
Key Takeaways
- Evidence of a victim’s drug possession is properly excluded when there is no credible alternate suspect and the evidence’s prejudicial impact outweighs its minimal probative value.
- A prosecutor may highlight the lack of evidence supporting a defendant’s theory without improperly shifting the burden of proof, particularly when the jury has been instructed on the presumption of innocence and the state’s burden.
- The defense of property justification is unavailable to recover stolen property once a theft has been completed; it applies only to prevent an ongoing taking.
- Mandatory LWOP sentences for first degree murder satisfy constitutional proportionality review when the offense is categorically grave.
Why It Matters
This decision establishes important evidentiary and sentencing principles in Colorado criminal law. It clarifies that courts may exclude evidence of a victim’s drug possession when it rests on pure speculation about unidentified alternate suspects, protecting victims from character assassination and preventing minitrials on collateral issues. The opinion also reaffirms that prosecutors retain significant latitude in argument during closing, particularly when responding to defense theories, so long as the jury remains properly instructed on fundamental principles like the burden of proof and right to remain silent.
The ruling on defense of property confirms that property owners cannot justify the use of force—even against non-owners—merely to recover property once taken; the statute’s protective scope is limited to preventing ongoing thefts. Finally, the court’s proportionality analysis provides guidance on when appellate courts may conduct constitutional review of mandatory sentences and underscores the heightened deference afforded to legislative judgments in sentencing for the most serious offenses.