SINGAPORE, Aug. 3 -- The High Court is grappling with how to deal with a rare case involving a 90-year-old man who killed his wife in what prosecutors described as an "overwhelmingly lethal" attack, while suffering from dementia and delirium and deemed incapable of making his defence.

CNA reported that Ridawi Morsudin, who was 88 at the time of the June 2024 incident, inflicted extensive sharp-force injuries on his 74-year-old wife, including a gaping wound from her jaw to her chest, multiple stab and incised wounds, and fractures to her skull, neck, spine and ribs. His grandson found her lying in a pool of blood, while Ridawi stood nearby mumbling incoherently.

Medical assessments later confirmed Ridawi was of unsound mind due to major...