A schozophrenic woman was killed by her husband who gave her 28 times her anti-psychotic medicine because she had cut the cable to his stereo equipment.
Hungt Kiat Tan fed his wife, Siew Kee Ang, 84 tablets instead of the three she normally took each day, the Supreme Court in Brisbane heard.
"This morning could be the last straw. Today I will kill my wife. No joke," the Courier Mail quoted Tan as he wrote in a book, which was found by police.
Tan, 58, pleaded guilty to murdering Ang, 53, in mid-March 2009.
He was a full-time caretaker for his wife and was also responsible for her taking medicines regularly.
Taking an advantage of his duty, Tan fed Ang all of her anti-psychotic medication in lots of seven tablets washed down with water.
Police interviewed Tan and, after initial denials, he admitted he had murdered his wife.
Justice Glen Martin said that there is no doubt that tablets caused her death and sentenced him life imprisonment.