It was a rerun of the episode "Sins of the Father", where Tony's dad is suspected of murder. Lt. Massey is killed with a wine bottle upside the head, and since Senior was known to have threatened him...
But of course, Team Gibbs found out whodunnit. It was the CEO of the company that Senior was working with to get funding for a resort. He found a backer, but Massey refused to pay him the agreed upon finder's fee because he only had a year to do it in. The CEO had threatened to fire Massey and some other people, and I guess was afraid Massey would try to retaliate. So he killed him.
Gibbs proved at the end that he's a fairly classy guy. When Senior's deal fell through, he couldn't afford to stay at the hotel he was registered at, so Gibbs put him up for a few days. (He also gave Senior a room to keep him out of jail; Senior was wearing a GPS monitor.) It was a great episode.
The thing that was ironic is that the episode aired at the same time that the L.A. County Sherriff's Office reopened their investigation into Natalie Wood's drowning. (Wood was Robert Wagner's (Senior) wife who fell off their yacht around Christmas of '81, I believe, after she got into a drunken argument with Mr. Wagner. A lot of people still believe he killed her in a drunken, jealous rage. He apparently thought she was having an affair with Christopher Walken, who was also on the yacht and whom Natalie was costarring in a movie with.)
I'm just glad that I got to watch it tonight. Mr. Wagner is a wonderful actor, and I love him as Tony's dad.
Edited: You know, I just thought of something -- it would have been funny if someone had had the line "Jeez, Tony, what is it with you DiNozzos being framed for murder? You've been set up three times [in "Frame Up", "Internal Affairs", and "Bounce"], now your dad is!" lol (Okay, maybe not...)