Weston's co-defendants were charged with many of the same crimes, but only she has been charged with murder.
All five defendants made history by also being charged with violating the federal hate-crimes act. U.S. Attorney Zane David Memeger said this marks the first time the law has been used to protect disabled persons.
"Shocking does not being to describe the criminal allegations in this case," Memeger said at a news conference before the court hearing.
He said the criminal enterprise known as the "Weston Family" operated from fall 2001 through October 2011 in Philadelphia, Texas, Virginia and Florida, and victimized six disabled adults and four children.
During that time, Memeger said, Weston and company lured the disabled adults to live with them and got control of their Social Security payments, ultimately stealing $212,000.
The victims were fed substandard food, beaten and threatened regularly and were "tied up and confined like zoo animals and treated akin to slaves," Memeger said.
Philadelphia police discovered four malnourished adult victims locked in a filthy Tacony apartment building basement in October 2011, which led to the arrests of Weston, McIntosh, Thomas and Wright. After being charged by the District Attorney's Office with kidnapping, false imprisonment, conspiracy and related crimes, the defendants were held for trial during a December 2011 preliminary hearing.
During Wednesday's court hearing, however, Assistant U.S. Attorney Faithe Moore Taylor told U.S. Magistrate Judge Thomas Rueter that the state charges are in the process of being dropped.
All five defendants could receive life sentences if convicted on all counts, while the decision on whether to seek the death penalty for Weston is being studied and the final decision will be made by U.S. Attorney General Eric Holder, Memeger said.
Rueter set an arraignment and bail hearing for Monday for the defendants, who are in custody.
The indictment's most shocking counts concern the deaths of two women identified as D.S. and M.L. When D.S. died in Weston's Philadelphia basement after being mistreated in June 2005, Weston ordered others to move the woman's body to a bedroom where an accidental drug overdose was staged before authorities were called, Memeger said.
M.L. was forced to cook, clean and babysit in Weston's Norfolk, Va., home and died there in November 2008 of starvation and bacterial meningitis. Weston also staged her body in a bedroom before calling authorities, according to the indictment.
"The physically and mentally disabled are among the most vulnerable in our society," Memeger said. "They deserve to be treated with respect and compassion, not violence."
On Twitter: @MensahDean