Most property crimes are crimes of opportunity, where thieves see a vulnerable target and take advantage of it as quickly as possible.
But the latest trend in property crime involves a little more planning, a little more patience.
It's a new twist on an age-old scam: Somebody or some group of people knock on your door -- looking for help.
Tucson Police burglary Sgt. Mathew Dietzman said they will try just about every trick in the book - from people trying to sell you something or offering to do yard work to the distressed parent who can't find her child.
"It's anything you can think of, asking to use your phone, my car's broken ... I need money -- I need a ride," Dietzman said.
What most of these have in common, he says, is they're complete lies.
The people knocking on your front door are criminals.
All they're doing is casing your property and trying to figure out if you're home.
"That's exactly what they're looking for," Dietzman says. "They hope no one's home. That means it's safe for them to go about what they want to do."
That's what happened at a midtown home just a few weeks ago.
An unsuspecting man in a red T-shirt acted like he was having some kind of problem with his bicycle.
Then he approached the front of the house and knocked on the door.
Brian Cunningham is owner of the house in question.
"They check to make sure that nobody's home," Cunningham said. "Then they come back (and attempt to break into your house). I have four security cameras that are pretty easy to see.
"Unfortunately, I've been broken into three or four times. This was kind of the last straw."
Especially after watching this whole scenario unfold on his own surveillance tape.
Shortly after realizing the house was empty, the suspect returned a short time later -- by jumping over a fence into the backyard.
But this time he was not alone.
He brought a friend along with him, who in just few moments enters the home through a doggie door and lets the other suspect in.
"It's horrible knowing they were in the house," Cunningham says. "And you know I have a puppy and fortunately he was in his kennel at the time. It really worries me that they would hurt one of the animals or more importantly, somebody else. Thank God nobody was here when they did it."
Thanks to motion sensors inside the house, an alarm went off just a few seconds after the intruders were inside, causing them to drop everything and make a run for it.
In this case nothing was stolen -- and everybody is OK.
But what if there weren't motion sensors inside?
What if somebody were sleeping in another room?
That's why we're bringing you this investigative report.
"If you feel that there's something wrong with it, call us," TPD Sgt. Dietzman says. "That's why we're here."
Maybe you didn't notice somebody knocking at your door because you weren't home.
But these crimes usually happen in waves and often along the same residential streets.
"They go around and look in neighborhoods," Dietzman says. "You see the box for the brand new 52-inch TV in the alley or in the dumpster. They know it's in there."
Which is why a little common sense goes a long way in protecting yourself and your property.
Keep your windows and blinds closed whenever you're not home.
And if somebody in your neighborhood doesn't seem quite right don't be afraid to call the police.
"If someone is coming knocking on your door and they're asking for help or asking to sell you something and they don't look legitimate, by all means call 911," Dietzman says.
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