Criminologists say serial killers often target people whose lives may be messy or off the grid -- prostitutes, runaways and drug users -- because their absences might not raise red flags, even for their families.
After pleading not guilty by reason of insanity, Sowell was convicted in July 2011 of 11 murders, a few rapes and other related charges, according to the Cleveland Plain Dealer. The court sentenced him to death.
After the bodies were discovered, other women came forward, alleging Sowell attacked them.
His home was in a neighborhood that care forgot.
His two-story house sat in a dilapidated neighborhood known as Mount Pleasant, where one in five homes were in foreclosure and at least a third of the residents receive food stamps, according to a study by Case Western Reserve University's Center on Urban Poverty and Community Development.
Neighbors and even a councilman had failed to realize that a stench wafting in the area around Sowell's home was rotting human flesh.
Some in the neighborhood complained then that another factor may have been in play: No one cared when 11 destitute African-American women died.
Trend: Escaping alive
More and more people who were abducted escape alive, a spokesman for a nonprofit organization that tracks missing children told Anderson Cooper.
"We are seeing more of them being found as survivors like the three women in Cleveland," said John D. Ryan, CEO of the National Center for Missing & Exploited Children.
But years in captivity can turn into decades of confinement.
"We actually celebrated this past summer the longest recovery of a missing person," Ryan said.
A boy kidnapped at age 2 was found 41 years later and reunited with his mother.
Despite the proximity of the House of Horrors and the similarities between these two grim cases, there is one difference that many were cheering Monday.
The girls who were allegedly abducted and held at 2207 Seymour Ave. made it out alive.