In that clip Henry says he killed three people. He shot someone at 16 after making them march into the woods and then he killed two more when he was 22, including one with an icepick. Although it didn't seem like he understood Robin's question about how old he was for the other two hits, so he just repeated 22. He was shitfaced though. I'm sure he made it up. He "remembered" a lot of things that didn't really happen. Including none other than John Gotti himself producing a "silenced .357 Magnum" (lol) from his leather trench coat and blasting Tommy DeSimone in the head. That was "revealed" in the last book he was involved with about Lufthansa.