JANESVILLE, Wis. -

Local law enforcement officials are urging parents to increase Internet restrictions on their children's laptops and mobile devices.

Even with restrictions in place, parents say it's hard to monitor everything their kids are accessing.

"It's too easy to come across things they shouldn't be seeing. There's so much out there, the violence, it's in everything," mother Courtney Hellmich said.

Hellmich's reaction comes after hearing two 12-year-old Waukesha girls stabbed their friend.

Police said the girls spent months planning the attack using the Internet.

The criminal complaint said that one of the girls told a detective they had to kill someone to become proxies of a character called Slender Man they learned about on a horror story website.

Now, Hellmich, a mother of six, said she's worried about what her children could be seeing on the Internet when she is not watching.

"One click and they could be into something they should have never seen," Hellmich said.

Internet-influenced criminal acts like Saturday's stabbing in Waukesha are why law enforcement agencies like the Rock County Sheriff's Office are pushing parents to use monitoring software, like "computer cop" on their children's Internet devices.

"It really is the Wild West out there, and it's a frontier of technology that we are just now getting a hand on. So it's going to take some time for law enforcement and our communities to really appreciate and understand how dangerous these sites can be," Sheriff Robert Spoden said.

The software allows parents to monitor their child's Internet use and flags dangerous words and images that they may come across. University of Wisconsin-Madison professor Joanne Cantor said parents can't rely on the software alone.

She suggests that parents have an open line of communication with their children.

“Just criticizing it usually doesn’t work. As kids get older, they’re less and less likely to believe their parent’s criticism, but if you can get them to talk about it, say ‘Well what do you think about that? What do you think would happen in the real world? What would people think of you if you did that?’ Let them talk,” Cantor said.

A communication approach Hellmich said she uses in her own home.

"I think a lot of it needs to come from the parents a head of time. This is what our standards are, these are what our morals are, and teaching them ahead of time before they even face those situations not waiting until it happens," she said.