Tell your dad not to get too worried about it. Criminals almost *never* use picking as a means of entry. And beside that, unless you're prepared to go to something in a high security lock (Medeco, for example), and pay a whole whack of money for them, there's not a lot out there that will be enough better to justify the change-over.
Indeed, Schlage locks tend to be better, but they would rarely stop someone who is skilled at picking. Nor would security pins. Etc... etc.. etc..
Go tell your dad that I have cheap locks and an alarm system. Works for me.
db