Ian Beale will never grow a pair so it is doubtful he will be the killer.
Ian is a spineless git, he didn't kill Archie. I reckon it was Janine.
It could have been Sam and Peggy takes the rap for her, hence her leaving and Sam goes back into hiding
Ian makes my skin crawl, such a sleaze ball. Very much doubt it will be him.
I'm surprised Ian even had the guts to steal Archie's laptop!