"According to a later confession by Hans Reiser to authorities, on September 3, 2006, Nina Reiser dropped their two children off with Hans Reiser at his mother's house, where he was living at the time. The pair got into a heated argument over Nina Reiser taking the children to the doctor, with Nina referencing that she had custody over the children, and so was free to do as she wished. Defense lawyer William DuBois later said that Hans Reiser alleged that Nina Reiser was fabricating illnesses in the children. Hans Reiser hit her in the face and strangled her to death."

https://en.m.wikipedia.org/wiki/Hans_Reiser

I do not read this as planned, but as "Handlung im Affekt", dunno the English term.