 What do all 3 crimes have in common?
There were Miss English and Miss Philicoff, the girls in the gilded teller cages. The three bank robbers looked like triplets. The third one, who carried a black satchel like a doctor's bag, walked quickly around behind the teller's counter and started filling it with money. The man who had first spoken herded the tellers, Mr. Featherhall and the customers all over against the back wall, while the second man stayed next to Mr. Anderson and the door. She fell unconscious to the floor, and all three of them ran out of the bank to the car out front, in which sat a very nervous-looking fourth man, gunning the engine. "It was four professional criminals, I thought you knew that.
 They were ended by unexplained phenomena and marked by the Scorpion.
 They were ended by unexplained phenomena and marked by the Scorpion.  They were carried out by The Scorpions, a new gang.  They were ended by the criminals being apprehended by the police.  In all 3 cases, something either melted or got too hot to handle.