JANESVILLE, Wis. -- Rock County investigators are looking into a 17-year-old victim's Internet activity for clues in Friday's triple homicide.

VIDEO: What Parents Should Know About MySpace.com

Danyetta Lentz, 38, and her teenage children, Nicole and Scott, were found dead in their Rock Township home, just outside Janesville, last week. Investigators said that they don't know whether there was a single assailant or multiple attackers.

Nicole Lentz, 17, had a MySpace.com Web page, and someone was logged into her account as late as the day the bodies were found, WISC-TV reported.

"(We want) to find out who these contacts were that they may have had on the Internet at the MySpace, and they might be able to offer us information as to the last 24 to 48 hours of these victims lives," said Rock County Sheriff Bob Spoden.

There are now 13 detectives working the case, WISC-TV reported.

Spoden said that three sets of detectives have searched the crime scene three times, and that they are now waiting for DNA test results.

Autopsies this weekend showed the three died of "complex homicidal violence." Sheriff Bob Spoden said that this means their deaths could have multiple causes.

Medical examiners still haven't released the cause of death except to confirm the three were victims of homicide.

The sheriff said that a tip hot line was established and that it is being staffed 24 hours a day.

Authorities are asking anyone with information on the case to call 877-262-3772. Spoden said that anyone with information, even with something that might seem inconsequential, should call the tip line. Callers can relay information anonymously, WISC-TV reported.

A gravesite has been donated for the Lentz family.

According to the Janesville Gazette, Ron and Delores Pagel donated the site after hearing about the homicides.

The Pagels said they have two extra graves at Oak Hill Cemetery and wanted to help out.

Funeral arrangements have not yet been set.

Many Teens Post Personal Information Online

Experts said parents might not know that many teenagers post personal information online, where anyone could view it.

Social networking sites like MySpace.com were set up as ways to gather marketing information. Teenagers would explain their interests and name their friends on a Web site for free.

Companies could then gather information on who was interested in their product.

Now, these Web sites have become a place where many teenagers feel safe enough to post some of their most personal information.

Increasingly, young people are using sites like MySpace.com to talk to friends.

"MySpace is like a teen thing. It's a high school, it's a middle school thing. A lot of people are naïve, they're not going to be like, 'Oh, I shouldn't put my age. I shouldn't put my address. They don't think about it before they do it,'" said Maegan Evans, a student at Oregon High School.

David Pallaske, 19, said he is cautious about what information is on his MySpace.com Web page.

"I don't even have my age on there, and my first name is all that you'll see on there. I don't have my address or anything like that. I'm very cautious," Pallaske said.

University of Wisconsin-Whitewater student Greg Gallmeier said he created his MySpace.com Web page while in high school.

"When I first got on I'd be on it at my house, and my parents would sneak up behind me and say, 'What are you doing?" Gallmeier said. "(They'd be) looking at the screen and trying to see the stuff on there, pictures and stuff like that. (They'd say), 'I don't know if you should be on that. Is that safe?'"

An expert on social networking said that theoretically the sites could be good for connecting people but that it is the attitude it's used with that could make it unsafe.

"The key problem is that a lot of the younger users of MySpace.com don't have that sense of what it means to go public with these things, and as a result they don't set their profiles to 'private,'" said Dietram Scheufele, a journalism professor at University of Wisconsin-Madison.

Gallmeier said he is careful on sites like MySpace.com, but he acknowledged that it has moved some of the center of the teen universe to the Internet.

"It's just like a phone conversation with your friends, you don't want your mom on the other line listening in, which is probably not a good thing on MySpace.com because (if) your parents either wanted to get one and got on one they could find you really easy."

The biggest safety suggestion from experts and law enforcement is to remember that any personal information online about teenagers or their friends could be seen by anyone.

Experts recommend removing that personal information and to have young people make their profiles "private" so the general public cannot access their personal Web page.