I believe the guy you're talking about may be Michael Corbitt (sp). He had some other theories about who killed Giancana, and Tony Spilotro was someone he mentioned. There were others.

I have no idea relative to Spilotro's whereabouts the night Giancana was killed. The most common theory I've heard is that Dominic "Butch" Blasi was the person responsible for killing Sam Giancana. No one was ever charged. Blasi was one of Giancana's closet friends. If you read the FBI files, Giancana once offered to lend Blasi something like $120- 130,000 to purchase some land. Blasi turned him down because he said the IRS would be all over him about where he got the money. Who knows what eventually happened? Maybe they "worked something out." Two points here: 1. Giancana's willingness to help one of his men, and 2. Some of your best friends will "do you in."

CHICAGO will probably have some additional information.