A Laci Peterson-like case? Eight-months pregnant woman shot to death, and guess what? Her husband is having an affair.
The evidence is all circumstantial, but... Staged burglary? Mean dog who would only let the family in the house but seemed to have done nothing? Gunshot residue on husband's shirt...or maybe not?
The Houston Chronicle's story on the case is not as good as the link above, but their reader comments, including some from people who knew the couple and land on either side of the guilt-innocence divide, are worth reading.