Seventeen-year-old suspect De'Marquise Elkins' mother, Karimah Aisha Elkins, 36, and his aunt, Katrina Latrelle Elkins, 33, were accused of "false statements or writings," court documents said.
The nature of the women's alleged false statements wasn't reported.
Both were held in the Glynn County Detention Center until they were released on $1,104 bond, CNN reported Tuesday.
A Brunswick police spokesman said investigators found a weapon and were trying to determine if it is related to last Thursday's shooting. It wasn't reported where the weapon was found or why police believe there could be a connection.
De'Marquise Elkins was charged with murder Monday for allegedly shooting a 13-month-old baby in the head. A second teen was also charged with murder, though his name hasn't been reported because he, at 15, is a minor.
Sherry West, pushing her 13-month-old son in a stroller last Thursday, told police she was approached by two males who demanded money and threatened to kill the baby.
She said one suspect grabbed her purse while the other fired a gun, a shot grazing her head and another striking the child in the leg.
"And then, all of a sudden, he walked over and shot my baby in the face," West said.
Puzzle-maker slips 'Murdoch Is Evil' into Rupert Murdoch's Sunday Telegraph
Wisconsin business offering 'therapeutic cuddling' forced to close