You could do this by storing a user_id in the session. And checking if the user still exist every request someone makes.

create a filter that checks if the user is still in the database and log him/her out if not

Auth::user(); // queries the database

You could save in the Users table a field that manage the remove action of the admin (example removed field as bool type) you could use Ajax with a timeout method in the layout.main.php view to observe all request of the User, and if the user removed has the field with a true value, you could send an event to the Application to force logout.

Hope it helps you.