This case is really interesting to me. I feel so awful for the children.
Apparently Michelle Nyce was having an affair with their landscaper. Several months ago, she said she broke it off when the landscaper began pressuring her for money, etc. Around the same time, Jonathan Nyce says he got a phone call from someone who later turned out to be the landscaper, demanding that Jonathan Nyce pay him $500,000 or he would release audio and video tapes of Michelle Nyce having sex with another man. Jonathan Nyce heard part of the audio tape and recognized his wife's voice.
The Nyce's pressed charges against the landscaper, but the case was eventually dropped. Jonathan Nyce says his wife had just returned from seeing this landscaper when a fight broke out and she was killed.
This article has lots of info: