So, I was playing and died (damn you maneuverability), and as far as I know, my character is now dead forever. I thought the stash was shared, but it seems it is per character.
Is there any way to get the items from a dead character?
Unfortunately, I think the items are lost forever. If your agent dies any items he was carrying and any items in his stash are non-retrievable.
The only way to transfer items across agents is to retire and agent, you get the option to name and allow your most used weapon to be retrievable by other agents and other people on your steam friends list.