This is a simple activity I adapted from somewhere on the internet to practice past questions with prompts on the whiteboard.
The teacher sits down and mentions he saw a robbery yesterday. The Students, with their insatiable thirst for knowledge, ask questions about it using the slide to help them form them.
When done, think together of some other situations where robberies may take place and then pair off the students to invent scenarios and practice using the language themselves. You could monitor the language and correct the errors afterwards or just gaze at the wall and think about something else as they do it.