State v. Carson, 151 Idaho 713

Defendant Carson was convicted of first-degree murder of his three-month-old son and sentenced to life without parole after the jury found utter disregard for human life as an aggravating factor.
The State sought the death penalty; a subsequent statutory aggravating-factor phase led to life without parole because mitigating factors outweighed aggravation.
Judge instructed the jury on utter disregard and related statutory language; the jury reached the required findings for life without parole.
Mother testified at trial about the relationship and alleged infidelity; Defendant sought to introduce extrinsic evidence of Mother's relationships to show motive/credibility.
Defendant challenged (1) exclusion of extrinsic evidence about Mother's conduct, (2) prosecutorial misconduct in closing, (3) a prosecutor’s reasonable-doubt remarks, and (4) the utter-disregard jury instruction.
Court affirmed the district court’s rulings and upheld the conviction and sentence.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Admission of extrinsic evidence of Mother's conduct	Carson argues Rule 404(b) admissibility for motive; 608(b) permits impeachment by prior acts.	Mother’s infidelity shows motive to lie and to preserve the relationship; extrinsic evidence is probative and not unduly prejudicial.	District court did not abuse discretion; evidence was extrinsic and prejudicial, and not admissible under 608(b); 404(b) analysis rejected.
Prosecutor's closing arguments concerning sympathy/credibility	Arguments appropriately framed to reflect evidence and not to inflame passions beyond the instructions.	Prosecutor improperly appealed to emotions and vouched for credibility of the mother.	No fundamental error; arguments did not render trial unfair under due process.
Reasonable doubt instruction and prosecutorial remarks	Closing remarks did not lower the standard of proof; the instruction itself was proper.	Prosecutor’s remarks could have lowered the standard if followed by the jury.	No due-process violation; jury instructions properly defined reasonable doubt and the jury followed them.
Utter disregard for human life instruction and sufficiency of the evidence	The instruction and evidence properly conveyed and supported by the record.	Instruction improperly defined utter disregard; evidence did not prove the requisite mindset.	Instruction aligned with Osborn/Arave framework; substantial evidence supported the finding of utter disregard.

State v. Osborn, 102 Idaho 405, 631 P.2d 187 (1981) (defined utter disregard for human life; guiding framework for aggravator)
Arave v. Creech, 507 U.S. 463 (1993) (constitutional limits on utter disregard; ordinary meaning governs)
United States v. Young, 470 U.S. 1 (1985) (prosecutor's advocacy boundaries; danger of implying guilt)
Deliberations on reasonable doubt—state cases cited, Phillips v. Erhart, 151 Idaho 100, 254 P.3d 1 (2011) (presumption jury followed instructions; standard review)
State v. Johnson, 148 Idaho 664, 227 P.3d 918 (2010) (I.R.E. 403 abuse of discretion; standard of review in evidentiary rulings)
State v. Perry, 150 Idaho 209, 245 P.3d 961 (2010) (unwaived-constitutional-error framework)