All four could face the death sentence if convicted.
The detention motion filed by Assistant U.S. Attorney David Troyer provided more startling details about the firebombing and other alleged plots linked to the brother-sister duo.
Neither Kaboni nor Kidada Savage seemed to care about the consequences of the firebombing, which authorities have described as one of the most horrific examples of witness intimidation in Philadelphia history, according to information cited in the motion.
A day after the arson, Kidada Savage had a discussion with Lamont Lewis, the drug dealer she allegedly hired to carry it out, prosecutors say.
"Yo, you seen the news?" she asked.
"Why didn't you tell me there were kids there?" Lewis replied.
With that, according to the prosecution, "Kidada Savage just smirked and then said, 'F--- 'em.' "
Those killed in the fire included the mother and 15-month-old son of Eugene Coleman, a Kaboni Savage associate who had begun cooperating with authorities.
A few days before the firebombing, prosecutors allege, Kaboni Savage, 36, told two other inmates at the Federal Detention Center that he had something planned for Eugene Coleman, whose nickname was "Twin."
Savage said Coleman assumed he would try to kill Coleman's brother.
"Watch the message that we send," he allegedly boasted. "Twin think we're going to rock his brother. F--- that. I'm going to hit that n----- where it hurt."
The detention motion also includes other new details about the firebombing, which occurred about 5 a.m. Oct. 9, 2004, including a description of how Lewis and codefendant Robert Merritt allegedly broke into the house in the 3200 block of North Sixth Street and set it ablaze.
"Lewis kicked in the front door and fired two shots into the house with a gun he had obtained from Merritt," the motion reads. "Merritt tossed two cans of gasoline into the living room, instantly engulfing the house in flames."
Many of the new details in the case are apparently being supplied by Lewis, 34, who entered a guilty plea earlier this year and is believed to be cooperating with authorities.
The six victims of the firebombing are among the 12 homicides cited in the pending racketeering case against the Savages, Merritt, and codefendant Steven Northington.
Eugene Coleman's mother, Marcella, 54, lived in the house with her infant grandson, Damir Jenkins. The other victims were friends and relatives of the Coleman family, including Tameeka Nash, 34; Sean Rodriguez, 15; Tahj Porchea, 12; and Khadijah Nash, 10.
Authorities alleged that Kaboni Savage ordered the murders from prison and that he frequently issued threats against Coleman, other potential witnesses, and their families. He used his sister, the government alleged, to gather information about where potential targets lived.
Besides setting the firebombing in motion, authorities charged that Kidada Savage posted the names of witnesses on an Internet website in an attempt to intimidate them. She did this, authorities said, using her "screen name . . . Dizmatic."
The government motion also alleged that when Kidada Savage was arrested last week after a superseding indictment was unsealed adding her as a defendant, authorities found "a handwritten list of the names and addresses of witnesses and witnesses' family members" in her car.
The homicides cited in the pending indictment, authorities charged, were carried out on Kaboni Savage's orders, which he issued in most cases while in prison.
Savage was convicted in 2005 of heading a major cocaine-distribution network in North Philadelphia and was sentenced to 30 years. Eugene Coleman was one of the witnesses who testified for the government in that case.
Those killed were either drug rivals, witnesses, or family members of witnesses, prosecutors have said.
Contact staff writer George Anastasia at 856-779-3846 or firstname.lastname@example.org.