URBANA - A man with a knife took money from two people.  Police say he held the knife to the female and got cash from the other person.  In Crime Watch tonight, this is the latest in a string of armed robberies.  It happened in the parking lot of an apartment complex in the 500-block of Griggs Street in Urbana.  The suspect was wearing a ski mask.  Police say, he approached the two people Saturday night, July 25th.  Dan Morgan with the Urbana Police Department wonders, "Why is he doing this? Why did he pick that area?  Why was he in that area?  And if you have someone desperate enough to do this, what are they going to do next?"  Sargent Morgan reminds us to be aware of our surroundings and check to see who's nearby from time to time.  It's not clear if the suspect lives nearby or just happened to be in the area.  If you have information about him, saw something or maybe heard something, call Champaign County Crimestoppers at 373-TIPS.  You can also send in a text tip on your cell phone or a web tip .  You don't have to give your name or testify in court and a reward is offered.