They had this case on Unsolved Mysteries in 1992. Dan maintained he didn't kill his wife and the cops framed him because he filed a wrongful death lawsuit because he felt they didn't get an ambulance for his wife fast enough. He declared that because he had a criminal record, admitted to gambling debts and his wife had life insurance, the cops just focused on him and ignored any other possibility.

UM also stated that a neighbor, who had some mental health issues, later confessed she and an accomplice had been to blame for the burglary and shootings.

It also said Dan married a friend of Carol's from the church 17 days after being sentenced. So I guess some people did believe he was innocent.

http://unsolvedmysteries.wikia.com/wiki/Dan_Montecalvo