By Carol Cavazos, CBS 11 News

DALLAS (CBSDFW.COM) – As a Christian, Diana Shipman thought she knew all about good and evil until she met him in the flesh.  “I’m telling you, I’ve never known evil like this. Never,” Shipman said. “He was a wolf in sheep’s clothing. He told me he was a college professor,” she said.

Had she done her homework on him, she would’ve discovered he was no professor. But there was something more serious.

“He had a history of rape and I knew nothing about it. I didn’t know who I was dealing with,” Shipman said.

“I hear horrific stories like that all the time,” Catherine Smit said.

Smit, a Private Investigator, says, hoping to avoid men like that, more and more women are turning to private investigators for pre-relationship investigations.

Internet dating, she says, has practically made them a necessity.

“Nowadays you move around all different places. You get on the internet and you can become who you want to be,” Smit said.

As a Private Investigator and former cop, Smit has access to records the ordinary citizen does not: marriage, divorce, bankruptsy, foreclosure, and criminal history.

Then, there’s always the possibility of surveillance.

Bill Albright is another Private Investigator who recently captured, on hidden camera, a woman’s boyfriend in a strip club.

“There we have him getting close and personal with one of the dancers on the stage,” Albright said.

Both investigators put together a list of red flags women should watch for.

* “What’s the matter, don’t you trust me?” He won’t give you a straight answer and he makes it seem like you’re paranoid for asking it.

* He never invites you over to his place. There’s always an excuse. He may tell you that his place is being remodeled or he’s staying with a relative for the time being. The truth is, he doesn’t want you to know he’s married or living with someone else.

* Takes his cell phone everywhere. He doesn’t want to leave it where you can possibily answer it or see who he’s been talking to.

* He’s secretive about making his phone calls. That’s because he doesn’t want you to know who he’s talking to.

* You can’t call him anytime you want. He can only call you. That’s because his wife or girlfriend might be with him when you call.

* He never introduces you to his family or longtime friends. Those are the people that really know him and could say something out loud if there’s someone else in his life.

* Stories and timelines don’t add up. He claims to have been in one place but then later tells you he was in another. You have to be a good listener to find inconsistencies.

* Comes on too strong. He wants to get married right away. He tells you that you are the love of his life when he really isn’t after your love. He’s after your money and credit. If you marry him and he’s in debt, you’ll become responsible for it or he could drain your bank account. .

* He’s too interested in your children. Child predators prey upon single women with children. He may even pretend he didn’t know you had children. He may suggest a stay at home night with the kids instead of going out with you on a date. It may look noble but he’s really trying to get to your kids.

*Beware of half truths. He may be going to an office party. But, he doesn’t tell you his girlfriend is going to be there too. Or he may be going out with a group of friends from work. But he’s invited a woman to meet him there too.

Investigator Smit says it costs only about 50-dollars for a basic background investigation.

“It costs a whole lot less to do a basic background check on somebody before you meet them than after you meet then and pay the price,”she said.

Private Investigators agree, it’s mostly the men who are pretending to be someone they’re not.

“I guess men, as a class, are just dogs. I don’t know,” Albright said.
After her experience, Diana Shipman would rather keep company with a dog, her daschund Tori.

“I’ll die alone rather than go through anything like that again,” Shipman said.