A 7-year-old Trenton girl was sold like a prostitute to a pack of perverts and gang raped by up to seven men and boys.
And the person who pimped out the grade-schooler was her 15-year-old stepsister, cops said.
"Let the boys do what they want to do," the teen told the younger girl as the leering lechers looked on - then stepped back and watched the men molest her.
"You don't even know what to say," Trenton Police Capt. Joseph Juniak said. "It's incomprehensible."
Residents of the Rowan Towers - a high-rise project near the New Jersey statehouse - were also aghast.
"Those people are monsters," said Gail Hall, 49, who added that she never lets her 11-year-old granddaughter roam the building alone.
A 21-year-old mom who goes by the nickname 'Sticks' said there would be blood if any man touched her 4- and 1-year-old daughters. "I would have not even called the police," she said.
Last night, Trenton cops were patrolling the grim hallways.
The 13th-floor apartment where the girl was violated appeared empty.
The horror show happened Sunday when the teen took the 7-year-old along to a party and left her unattended in the living room while she had sex for money with several men in a bedroom.
When she was done, the teen gave her stepsister a wad of cash and told her to let the men "touch her," said Juniak.
"It went from touching to straight out assault and rape," he said. "They threatened to kill her if she screamed or told anyone."
Meanwhile, the girls' parents had called police, fearing the troubled teenager had run off with the child.
Cops were questioning the parents when the little girl was brought home in tears by two kindly women who found her on the street.
The 15-year-old was charged with aggravated sexual assault, promoting prostitution and other crimes. She was in a juvenile lockup and prosecutors plan to try her as an adult.
More than a dozen people were at the party and cops were trying to identify the culprits.