Ok, I do have one for you guys. Never figured this one out;)
A lone thief robbed a bakery of 2 dozen donuts. Local Police interrogated 4 suspects who all knew eachother. 2 of the 4 made true statements and 2 lied. The liars included the thief. If police had been aware of the foregoing facts they could have deduced who the thief was.
Horrible Andy said "Ben is the thief"
Dirty dog Ben said "Cal took the donuts"
Clever Cal said "I'm not the theif"
Dasterdly Dan said "Ben isn't telling the truth"

Who was the thief?

Question

Ok, I do have one for you guys. Never figured this one out;) 
A lone thief robbed a bakery of 2 dozen donuts.  Local Police interrogated 4 suspects who all knew eachother.  2 of the 4 made true statements and 2 lied.  The liars included the thief.  If police had been aware of the foregoing facts they could have deduced who the thief was.  
Horrible Andy said "Ben is the thief"
Dirty dog Ben said "Cal took the donuts"
Clever Cal said "I'm not the theif"
Dasterdly Dan said "Ben isn't telling the truth"

Who was the thief?