C# list sort by two columns

Question

I have a C# custom object list that I need to sort by two different variables one is a boolean and the other is a string. I can sort by either of the criteria, but

Answer 1

result.Sort((x,y) => x.CheckedIn==y.CheckedIn ? 
  string.Compare(x.LastName, y.LastName) : 
  (x.CheckedIn ? -1 : 1) );