'Neighbor From Hell' Uses Curses, Handmade Signs to Harass Minn. Family

Sept. 12, 2012— -- The friendly sights and sounds of a neighborhood block party may seem typical, but to one family in White Bear Lake, Minn., it feels nothing short of miraculous.

"This is a great group people in this neighborhood, but it's been a ghost town for two years," said Greg Hoffman in an interview with "20/20."

Greg Hoffman, 56, and his wife, Kim, saw their close-knit, congenial community turn into a ghost town because of Lori Christensen, 49, whom they call "the neighbor from hell."

Watch the full story Friday on "20/20" at 10 p.m. ET

Life in the idyllic Minneapolis suburb had been fine, the Hoffmans said.

"The kids would play with each other. ... Since [Christensen] was a single mom, we would help her out with blowing her snow in the winter, helping her with things like that," Greg Hoffman said.

The Hoffmans said cordial turned to combat five years ago.

"Lori's daughter and us were playing in the yard, painting each other's nails, and she opened the nail polish and just started pouring it in my hair," said the Hoffmans' daughter Keira, 10.

"[Keira] was crying and upset, and she had some fingernail polish in her hair and on her face," said Kim Hoffman. "I didn't think it was that big a deal. I just went over to Lori's, and I said this was what had gone on. I guess immediately she pretty much went off on me. She was yelling and screaming. I turned around and started to walk away."

But the Hoffmans were about to learn that walking away from the wrath of Lori Christensen wouldn't be that simple. And just how vicious her attacks could get became clear when Kim Hoffman, a recovering alcoholic, relapsed and suffered a terrifying overdose of alcohol and pills.

Kim Hoffman collapsed in front of Greg, leaving him and their kids shocked and not knowing if she would live. They called 911 and rushed Kim to the hospital.

The commotion in front of the Hoffman home did not go unnoticed by Christensen, who soon found a way to use the incident against Kim.

"The kids were all playing," said Greg Hoffman, "and Lori came up into the cul-de-sac and started berating the kids, and cussing and swearing."

"I walked up there," said Kim Hoffman, "and I didn't even say anything to her. I said to Keira and Kylie, Come on, girls, let's go. And Lori looked at me, and she basically told me, 'You can't effin' take them. I'm still talking to them.'"

"I took their hands and turned around and kept walking home," Kim Hoffman went on. "And she starts swearing at me: 'You effin' fat whatever, you should have died. Why don't you drink some more scotch?' I never turned around, and I had my two girls' hands, and I just squeezed them and we kept walking in."

This began a string of similar incidents, and the Hoffmans started calling the cops, who became regular visitors to the neighborhood. At first the authorities didn't know whom to believe.

"It took quite a while for Kim and Greg Hoffman to convince me," said White Bear Lake Police Chief Lynne Bankes. "I needed proof beyond a reasonable doubt."

Bankes urged the Hoffmans to gather video evidence of Christensen's harassment, a move that proved to be a game changer in this conflict on the cul-de-sac.

When the Hoffmans' 15-year-old son, Jake, had a birthday party, the camera was rolling for Christensen's latest outburst.

"The kids were out there shooting baskets," Greg Hoffman said, "and Lori took out the remote-control cars and was swerving, [saying], 'I'm too drunk to drive.'"

"She started calling me a 'son of an alcoholic' in front of my friends, and it wasn't something my friends were aware of, so it was an embarrassing situation," Jake Hoffman said.