I've just been in a ranked game (that has been dodged by another player) and a player was just trolling from the start. I could go and look on it's LoLKing history and for at least 10 games he's been trolling every game.
That begs the question, can you report without playing the game with the troll?
There is no in-game means to report somebody who you have not played a game with. I wish I could tell you more, there MAY be a means to email riot about such trolls. The next best thing I can mention is the forums, and btw, this guy has already been reported on the forums. ;-)
There have been cases in the past where Riot staff have recommended submitting a support ticket in order to report a player outside of the in-game system. The ticket system allows you to include screenshots, so if you can document your case there might be a better chance of action against the griefer in question.
No, you cannot. But, you can send a support ticket. Attach his lolking profile/ nickname/ server etc. I am sure riot will do its best to take care of it.
