Justin Ross Harris was convicted of malice murder and child cruelty after his 22-month-old son Cooper died of hyperthermia in a car Harris left outside work. Harris said he forgot the daycare drop-off; the State argued he acted intentionally to pursue sexual relationships. The jury also convicted Harris of three sex offenses against a 16-year-old girl. The Supreme Court of Georgia held the evidence sufficient but ruled that needlessly cumulative and highly prejudicial sexual-activity evidence, including messages involving minors, enlarged photographs, and prostitution, should have been excluded under Rule 403. The trial court also abused its discretion by denying severance of the sex-offense counts after treating their supporting evidence as admissible to prove the Cooper crimes. Because evidence of intent was disputed, the Court could not find these errors harmless: it reversed the five Cooper-related convictions and affirmed the three sex-offense convictions. For retrial, it upheld disclosure of the defense expert’s interview notes and use of a properly founded three-dimensional car model, but held Harris should have been allowed to question a detective about allegedly false warrant-affidavit statements. Justices Bethel, LaGrua, and Colvin concurred in part and dissented in part.