BALTIMORE (WJZ) — Three Maryland men are behind bars, charged this week in separate child porn investigations.

One man from Montgomery County, is accused of filming the material himself.

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The number of child porn cases in Maryland has skyrocketed over the last two years. Police believe they have three pedophiles off the street, accused of raping girls as young as four years old.

“Your mommy can’t save you” —  chilling words in the federal indictment of a Montgomery County man, who is accused of raping young girls and filming it for years.

“Number one, the defendant allegedly was personally abusing children. Number two, the children were very young. And those are the factors that make a case particularly egregious,” says Maryland U.S. Attorney, Rod Rosenstein.

Kyle Thompson, a 31-year-old man from Burtonsville faces 18 federal counts of producing child pornography, plus three state counts of child sex abuse and four counts of sex offenses.

Investigators believe he’d prey on young girls by getting close to their mothers.

Adam Rosenberg of the Baltimore Child Abuse center says parents have to ask the tough questions.

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“It takes a community to protect children,” he says.

“What’s really important is vigilance on the part of adults who have contact with children. And I also think it’s important that we’re communicating, and we’re communicating with our children to make sure they’re comfortable with certain people.”

Maryland State Police arrested two other Maryland men this week in separate investigations.

Police have charged 21-year-old Fallston man Christian Alsup with sending and receiving child porn online, and 19-year-old Casey Merriman from Caroline County is accused of abusing multiple children in Maryland and Delaware, and having child porn on his computer.

Thompson, who is the only of the three facing federal charges, is due in court soon.

Thompson was caught thanks to an anonymous report given to police. Authorities anticipate more victims will still come forward.

Thompson faces a minimum of 15 years in federal prison if convicted, but could face up to 30 years for each of the 18 counts.

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