Transcript for Keep Your Belongings Safe in a Hotel Room
It's 7:39 we're back now with gma on the lookout and the summer travel heats up, we're investigating just how secure you and your valuables are at a hotel. Check out what our hidden cameras uncovered and how you can prevent becoming a victim when you check in. This thief walked into a hotel last month as a couple is sleeping. Moments later, he flees. How to prevent that from happening to you. We conducted an experiment. A guest arrives at a downtown Richmond, Virginia, hotel. But this guest is actually a gma producer, approximately 20 minutes prior with three undercover cameras rolling, bill Stanton shows up at the same hotel but he's not here to check in. I'm waiting, looking at his car, what watch he's wearing the luggage he has. Reporter: Stanton is playing the role of a would-be thief. When I see an opening that's when I approach and that's when I hear the magic words. I follow him right to his door. I have his name and his door number. Reporter: Armed with just two pieces of information, Stanton is about to show us how vulnerable we can be during a hotel stay. The waiting game ends the very next morning while our producer goes to the gym to work out. He comes with his workout outfit. As far as I'm concerned the clock to get into that room starts right now. I have at least 30 minutes to do what I need dor. Reporter: His plan so bold it's almost ridiculridiculous. He goes to the front did desk and asked them to clean our room. Stanton simply walks in as if it's his own room. He has our producer's permission. Otherwise this could be the beginning of a crime. I'm so sorry, can you give me two minutes? It doesn't take long for me to find everything right by the phone and what is it? An expensive watch and a valet ticket to his car. Yes, I'm in room 1112. Can you please bring up my car right now. Reporter: 150 minutes into our experiment. Our producer is working up quite a sweat, but Stanton not so much. There we go. Reporter: They ask for the ticket which Stanton claims he doesn't have. But they look at the name on stolen luggage and off he goes. It's easy as that. Reporter: Later that day, at a nearby hotel, Stanton tracks another "Gma" producer. Once again, right to the front desk. Listening to the name, room exchange. Reporter: When the producer leaves the hotel, Stanton sees his opening and our would-be thief springs into action, again pretending to be someone who he's not. From a house phone, Stanton calls for housekeeping to our room. But he sends them away. You're off the hook. I'm going to jump into the shower. Reporter: With the room to himself, Stanton has his mind set on a bold unlikely scenario. I'm in the room. Reporter: You heard it a hotel room safe and moments later, the gentleman from security arrives to help. That's right, she's wide open for you. Perfect. I got his cash, credit card and his laptop. It put it all in his luggage. The first hotel you saw in the piece, they have taken steps to on the short fall of security. We want to bring safety and security expert bill Stanton. Oh, my goodness. Yes, yes. Obviously you're not surprised? Well, security is a priority it's not the top priority. It's more about comfort and service. The tips when you should do when you approach the front desk, take your I.D. Don't say the name out loud. Show your I.D. You got -- you say the number one takeaway -- Zip your lip, push your license forward and let them check you in. Other great tips? With the safe it's anything but fail safe. Put your valuables in. If you have those expensive family items, go to the front desk and ask if you have a safe there or wear it on your person. Don't count on the hotel. Count on yours. Go to "Good morning america."com on Yahoo! For bill's top five tips. It's pretty surprising and there's more to come tomorrow, robin and George, wait until you see. Lara, thanks very much.
This transcript has been automatically generated and may not be 100% accurate.