Authorities say two girls are lucky to be safe and sound tonight.

Meanwhile, a 26-year-old man is behind bars after police say a teenager he met on MySpace, and the girl's 11-year-old sister, met with him in person Wednesday night.

Police say a 16-year-old Elkhart girl met 26-year-old Matthew Sanders about two weeks ago on MySpace.

Sanders is now being held on a preliminary charge of contributing to the delinquency of a minor.

While police continue to investigate, an expert says this should be a warning to other parents to keep an eye on what their kids are doing online.

Elkhart police believe the 16-year-old met Matthew Sanders on MySpace, where he posed as a 19-year-old from Mishawaka, about two weeks ago

“It’s a very common occurrence of people meeting on social networking sites like MySpace, Facebook; it’s very common that the people set up profiles lying about their information, who they are, how old they are,” said Mitch Kajzer.

Another strange detail: Sander's web-page listed himself as married, and he lately referred to his wife as "Steph." The 16-year-old's name is Stephanie, and there are pictures of her on his web page.

Kajzer, who worked on the now-defunct high tech crimes team with the St. Joseph County Prosecutor’s office, says it's alarming how often minors enter into the picture in these online meetings.

“The actual adults meeting children online; it’s scary how frequently it does happen and how often people would meet with me thinking I was a child,” Kajzer said.

The scenario Kajzer used to simulate undercover came true last night.

Luckily, police were able to find Sanders and the girls quickly in Mishawaka, after tips from the girls' mother, and the mother of one of Sanders' children.

“It seemed kind of odd that the 16-year-old took her 11-year-old sister along with her. I guess it kind of shows that she really thought there was absolutely no danger,” Kajzer said.

Meanwhile, Kajzer says paying attention to what your kids are doing online, and possibly even installing monitoring software, is almost a must these days.

“A kid will scream, ‘it’s an invasion of my privacy you can't look at my stuff!’ No. Any kid living in a house with an adult, any parent should be reviewing and seeing what their kids are doing online,” Kajzer said.

Sanders was also wanted on a warrant out of Washington state for a drug offense, and residential entry.

Meanwhile, Elkhart police say the two girls are not really cooperating with this investigation, so at this point all they could charge Sanders with is the misdemeanor charge of contributing to the delinquency of a minor.

Meanwhile, Kajzer says files on Sanders’ or the teenager's computers could be incriminating, as well as their personal files on MySpace.

But police say they do not have probable cause to seize those items at this point.