Frankly, I have a lot of trouble buying that as a motive. Michael could easily divorce Terri and marry Jodi. The fact that Jodi is Catholic and they would have to wait a few more years to have a Church wedding is meaningless. Catholics have civil ceremonies all the time.
Hmmmm... then why do so many other husbands chose murder over divorce???/ Is it that Terri would get half of his property, and he might be forced to provide spousal support?