In her testimony, Barbara Savage said Kaboni tried to befriend Coleman, who she said was lying about her son: "There was a time I thought he was a nice guy."
The firebombing killed Coleman's mother, son, and four relatives.
Savage is serving a 30-year term on trafficking charges, but faces the death penalty if convicted of racketeering and murder.
The trial, which began Feb. 4, continues in U.S. District Court as accomplices accused of helping Savage carry out the firebombing present their defenses.
On April 1, Lamont Lewis testified that he firebombed the Coleman family's North Sixth Street home in a predawn attack Oct. 9, 2004, that killed six, including four children, allegedly on order from Savage in prison.
Lewis, 36, confessed to 11 killings, which include the six firebombing deaths and several homicides that had been unsolved.
Lewis said he decided to cooperate with the federal prosecutors to avoid the death penalty and "for the victims and their families. So I can show my kids that what I was doing was wrong."
In her video testimony, Savage's mother recalled the night before the firebombing when Lewis rang the doorbell of the Savage family's North Philadelphia home and was allowed inside. While inside, he spoke on the phone with Kaboni Savage, who was calling from prison. During that call, Savage also spoke with his sister, codefendant Kidada Savage, his girlfriend Crystal Copeland, and his mother.
Prosecutors say Kidada Savage passed along murder instructions and helped plan the firebombing. Her lawyer, Teresa Whalen, on Tuesday called a witness to the stand who testified that Kidada Savage played no role in the firebombing.
The witness, Larry Harcum, 39, was in the Federal Detention Center with Lewis in 2008. Harcum testified that Lewis talked with him about the firebombing and admitted to being involved in the arson, but said Kidada Savage had nothing to do with it.
Assistant U.S. Attorney Steve Mellin aggressively cross-examined Harcum. "You know inmates often lie to each other?" Mellin said. "You don't even know if what you hear is the truth. Is that right?"
Harcum agreed that inmates gossiped and didn't always speak the truth.
Then Mellin told how Harcum had pleaded guilty in 2004 to gun charges, killed someone in a 2003 vehicular homicide, and was discharged from the Navy with less-than-honorable terms in the early 1990s, among other things to challenge Harcum's credibility.
Harcum admitted he lied to a probation officer about college studies, but stuck by his main testimony: "I'm not lying," he said, "about what I said about Lamont Lewis."
Savage and codefendants Steven Northington and Robert Merritt face the death penalty if convicted. Kidada Savage faces life in prison.
Contact Sulaiman Abdur-Rahman at sabdur-rahman@
phillynews.com or follow
on Twitter @sabdurr.