JEFFERSON COUNTY, Colorado (CNN) -- A warning for parents -- if you monitor your child's internet and cell phone activity, you might be missing something. Child predators are using special mobile apps to target victims.
A mother who wanted to remain anonymous said it happened to her 14-year-old daughter.
"I'm scrolling through this and I'm like, Oh my gosh, like oh my gosh, who is this person? I was scared to death. I've heard stories about people that do this. That's why I was trying to be so vigilant about watching her activities," the mother said.
This mom monitored her daughter's online activity and checked her cell phone, but her daughter was using a texting app that mom wasn't looking for.
"Parents aren't aware of them, and so kids are using those applications to communicate in a manner that their parents will never ever know about because most parents don't go through every single app," Detective Mike Harris with the Jefferson County District Attorney's Office said.
Detective Harris focuses on internet crimes against children and says these texting apps concern him.
"A lot of kids post too much personal information," Detective Harris said.
Detective Harris says the most popular apps are "Text Free," "Text Now" and "Text Plus." Members who use these apps can chat with each other, and that's how a criminal can get access to a child.
Harris says it's not uncommon for predators to ask for naked pictures, and then it escalates from there.
"Naked pictures are the fuel that gives the predator their stimuli until they can actually meet that live child," Detective Harris said.
Detective Harris has arrested over 500 people over the past eight years.
"I'm always amazed because we aren't arresting people that aren't smart. We are arresting professionals. Businessmen. I've arrested people in law enforcement. It's not just that low element of people that you think would commit crimes. These are people in society that no one ever would imagine," Detective Harris said.
This mom learned of her daughter's texting activity by accident and caught it early, but says her daughter is still shaken.
"Unless you physically know that person that you're talking to, and you have gotten that phone number from them, you should not talk to them -- period," the mother said.
It's a conversation she hopes every parent and child will have.
There are several mobile texting apps available. There's also an app for parents, called "My Mobile Watchdog," that can help you track a child's cell phone and texting activity.
The texting app companies say they are taking steps to protect users.