In this way...

after you query the database for authentication, once it is succesful, you can directly transfer the user to the respective page if you are using different pages for user and officer without any session variable

if the same page then after adding to the session

retrieve the value from session using

string userType = Session.Item["userType"].ToString();

if (userType == "User")

{

//   write your code related to user

}

else

{

   //officer related code...

}