Home Invasions: Why They Aren't Always Random

These criminals know what they're after, and their new secret weapon is the victim.

Southern California police say they're dealing with an increasing threat: robbers targeting homes while the victim is inside.

Robbers get to know the neighborhood — the patterns, the people, the rhythms. Somehow they track the victim and the valuables they keep in their home.

"Get on the floor, head down, don't move," recalled Diana Mandt. "I can see his face now. If I close my eyes, I can see the whole scenario."

Two armed intruders broke into Mandt's Hollywood Hills home.

"I heard my husband screaming," she said.

One intruder terrified her, and the other was downstairs yelling at her husband.

"They kept asking, 'Where's your stuff?'" she said. "My husband and I kept saying, 'What stuff?'"

What they wanted was locked in a safe next to what the couple wanted to protect most.

"It was right outside my daughter's bedroom," she said.

The robbers took off with all of their jewelry.

"My husband started screaming for me, but I was afraid to answer him because I didn't know if they forgot where I was," Mandt said.

When she didn't respond, her husband feared the worst.

"My husband said his stomach sank, because I wasn't answering, so he thought something had happened to me," she said.

Home invasion robberies are dangerous, but these crooks have decided it’s worth the risk.

"They're pretty much all over the place," Garden Grove Police Detective Ed Wilson said.

Wilson, who's been with the department for 25 years, said last year the numbers were unlike what the city had seen before: six home invasions in six months. He says none were random.

Beyond tracking the patterns of the neighborhood, police say robbers also take into account how likely it is their victim will fight back, making the elderly and kids home alone some of the most vulnerable targets.

"There were only children at the house at the time (of a home invasion)," Wilson said. Suspects knew that.

In one incident captured on surveillance video, a man pretending to deliver flowers rings the doorbell until someone answers.

"He's reaching for a weapon right now, and a second guy appears from nowhere," Wilson described. "Then the third guy. Now they're in, just like that."

Since the attack, Mandt has launched her own neighborhood watch and is working to get private security for the neighborhood. She's determined to never be a victim again.

"It changes you," she said. "It leaves an imprint on your brain and your heart."

Police say you are your own best defense. To protect yourself, authorities recommend talking to your neighbors and getting to know the community, keeping your eyes open for anything out of the ordinary, and trusting your instincts.