Brenda sees an I-Pad on the porch of Cindy’s house, takes the I-Pad to her home, and tells everyone she owns it. David, wielding a gun, forces Emily to give him her smartphone, and runs away with it. Frank breaks into Grace’s apartment, takes a laptop, and leaves. Halley sells Ingrad an expensive camera for a fraction of its value, admitting that the camera is stolen property but claiming that she is not the thief. Which of these acts are crimes, and what are the differences among them?