The concepts of mens rea and actus reus of crime are essential in criminal law. Consider each of the following scenarios and discuss whether both the actus reus and mens rea are present such that a criminal charge may be proven:

(1) Tony is shopping at a book store when he runs into an old teacher from college. The two decide to leave the store to grab a bite to each. Tony forgets about the book he was holding under his arm when his old teacher approached, as he was deciding whether to buy it. He walks out of the store with it under his arm. Potential charge: Theft 

(2) In line to buy tickets for concert, a friend asked Morgan to hold her purse while she went to the bathroom. Shortly thereafter, a drug sniff dog on the grounds that day stopped in front of Morgan and alerted on the purse she was holding for her friend. The police perform a search of the purse and find drugs. Potential charge: Unlawful Possession of a Controlled Substance

(3) Jim lost his temper in a retail store one evening and was charged with assault on a store clerk. Because he felt that an item offered for sale was priced too high, he slammed his fist down on a display table, sending a metal sign flying off, hitting the store clerk who was standing close by, cutting her cheek just below the eye. Potential charge: Assault