A judge has found Manfred Uhle, now 88, murdered his wife, Wanda, in their home in Canberra's south last year.
He was charged with murder, but was later found unfit to plead to the charge.
Uhle remains in custody and the matter will return to court in October.
A man who was found unfit to plead to a charge of murder did kill his wife, an ACT Supreme Court judge has found.
Manfred Uhle, now 88, was accused of stabbing his wife Wanda, 78, to death in their home in the Canberra suburb of Gordon in June 2024.
He was charged with murder, but was earlier this year found unfit to plead to the charge, requiring ACT Supreme Court Justice Andrew Muller to hold a special hearing of the case.
Justice Muller has now determined Uhle murdered his wife.
"It is beyond reasonable doubt that Uhle stabbed his wife repeatedly with a knife, resulting in her death," his reasons for the decision said.
He also determined Uhle's actions were voluntary.
"His was voluntary in the sense that his movements were controlled and administered repeatedly; he was conscious and, to the extent his consciousness was impaired, it was not impaired so as to deprive him of the will to act," Justice Muller noted in his decision.
At the time of the murder, the couple had been in a relationship for about 60 years.
In the months leading up to the murder, his family noted Uhle had experienced episodes of confusion and memory loss which continued to deteriorate.
Uhle has been in custody since the day of the murder.
As noted by Justice Muller, the prosecution argues the only suitable way forward is an order remanding Uhle in custody for immediate review by the ACT Civil and Administrative Tribunal (ACAT) under mental health legislation.
"In making that submission, the prosecution accepts detention in a correctional facility should be a last resort; but no other option presents itself at the present time," Justice Muller said.
Justice Muller said he would allow the parties in the case to explore the issue further, and whether that could include releasing Uhle to facilitate an ACAT assessment for the purpose of making a mental health order.
The matter will return to court in October.