2 user types - shared sessions controller?

All -

Don't you love it when someone prefaces their discussion with being
new to Rails?

I have a common user type for my application, and recently added a
second model for a different type of user - different rights,
different tools, etc. I'd like to keep the two models separate - and
wasn't convinced that STI was right for my situation. Therefore...

I'd like to keep the user types separate, but was hoping to share the
sessions controller. Is there a way to modify the session controller
below to allow for two types of users to access it. I started by
making a completely separate sessions controller for the other user
type (let's say user2) - but it certainly doesn't seem DRY.

Should I try to edit the controller below? Use STI or Polymorphic?
Other? Help.

class SessionsController < ApplicationController

  def new
    @title = "Sign in"

  def create
    user = User.authenticate(params[:session][:email],
    if user.nil?
      flash.now[:error] = "Invalid email/password combination."
      @title = "Sign in"
      render 'new'
      sign_in user
      redirect_back_or user

  def destroy
    redirect_to root_path