There are keys to just about everything.
But when it comes to your home, that's one key you want to keep to yourself.
"It just doesn't make sense for you to buy a lock that somebody else has a key to, period. I would like to know that my key is the only one that fits the lock."
Lock expert Glen Peifer is talking about a little known secret most consumers never even consider.
That is, when you buy a mass-produced lock, there's a very good chance somebody else has the key to your home.
"Maybe they think well what are the odds?" Peifer says. "Well I think if they really knew what the odds were, they would choose not to do that."
The odds are not in your favor when buying entry-level deadbolts, Peifer says, because most retailers only carry a limited number of different keys for each brand of lock they sell.
"I would say it would be very low. It was probably under ten or twenty," Peifer says.
We asked Home Depot and Lowe's how many different keys are available in their inventory of locks.
Home Depot said, "We don't break out the information your are requesting."
While Lowe's told us, "We aren't able to provide information on inventory."
That's when we hit the streets to find out what you think.
"My mom always used to say you get what you pay for," says Ginger Watson.
Watson was pleased with the price of a deadbolt she just bought at a big box store.
"Nine dollars and 97 cents," she said, holding her new purchase. "That wasn't bad."
But when we showed her (by matching the serial number on her key with another inside the store) it how easy it was to match another key with her new lock -
"My keys, your lock," our undercover representative said, holding the two items. "Ok, it opens."
"Wow," Watson said, shaking her head. "Scary, because someone can be helping me in the store, look at the number...here you go ma'am, memorize it, grab the same thing right quick or wait and just trail me home."
So just how prevalent is this problem?
And what are manufacturers doing, if anything, to stop it?
Take lock manufacturer Schlage, for example.
The company manufactures 30,000 different keys.
A spokesperson for Schlage says they constantly rotate the thousands of keys they ship to retailers.
But how often are retailers actually rotating their inventory?
At one Home Depot, we found seven Schlage deadbolts on the shelf.
All seven had the same key.
Out of nine handle and deadbolt sets, there were only two different keys available, meaning every other customer would have matching locks on their doors.
"There's a lot of fear and hype surrounding locks and things of that nature."
Tucson All-State agent Keith Duncan puts a little perspective into the deadbolt dilemma.
"All someone does is pick up a rock and throws it through your window, so if somebody wants in they're gonna want in," Duncan says.
So then what can we do to better protect ourselves?
First and foremost, Duncan says, more people need to lock their windows and doors in the first place.
"Forty-three percent of all the property crime that happened in Arizona last year is what we call unlawful entry," Duncan says. "That's where somebody just walks through your door because it wasn't locked."
Second, choose a deadbolt that suits your family's needs.
You don't need to spend three or four hundred dollars on the most sophisticated locks out there.
In fact, you can buy a Smartlock by Kwikset that allows you to customize your key for less than 50 bucks.
"When you put it in there and give it a turn," Duncan says, "it puts a learning mode to say, ok, I am ready to accept a new key."
Bottom line, the key to protecting yourself and your home isn't always the most expensive option.
But there is some truth in getting what you pay for.
Rather than buying that easily duplicated deadbolt for less than ten bucks, invest in something you can customize yourself.
Because if you don't you could get a lot more than you bargained for.
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