Mersadies Shelton and Daniel Mathis had previously been charged with possession of Quick's stolen Toyota 4Runner.
Mathis allegedly discharged a firearm at a teenager before a Super Bowl party. The father of the teen had said that the 4Runner was used as Mathis' getaway vehicle.
Louisa Commonwealth Attorney Rusty McGuire would not comment on the decision to nolle prossquei those charges.
However, legal experts tell CBS 6 prosecutors can directly indict Mathis and Shelton if the evidence against them is strong enough. Shelton and Mathis each had multiple felony charges certified to the grand jury in relation to the Super Bowl shooting.
Mathis is accused of pulling a gun while attempting to rob a group at the party, before shooting a man in the ensuing scuffle. Meanwhile, prosecutors said Shelton struck the homeowner in the head with the gun after Mathis dropped it during the struggle.
A third suspect, and sibling to the other tow, Shantai Shelton, had multiple felonies certified to the grand jury as well, none having to do with the Quick investigation. Shelton was arrested, on outstanding warrants, with the other two in Alexandria at the beginning of the Quick investigation.
Shelton is accused of drugging and robbing an elderly man, who she was living with at the time, of guns and credit cards.
Shelton is also charged with trying to sell stolen rings at a jewelry shop.
"There's just a lot of things that we don't know," said their step-grandfather Danny Trobaugh.
He doesn't believe they were ever in Cpt. Quick's vehicle.
"I have not heard it from them, I've only heard innuendos," he said.
A grand jury will meet on May 5 to hear these charges and any others the prosecution may decide to bring.
All three are being held without bond at the Central Virginia Regional Jail in Orange County.