BRUNSWICK, Ga. -

A Georgia grand jury has indicted a 17-year-old suspect in last week's fatal shooting of a baby in his stroller and in another unrelated shooting 10 days earlier in a robbery attempt.

The 11 counts returned Wednesday against De'Marquise Elkins include malice murder in the slaying of 13-month-old Antonio Santiago (pictured, below). The indictment says Elkins shot the boy in the face with a .22-caliber revolver while trying to rob the child's mother in coastal Brunswick last Thursday.

The indictment charges 15-year-old Dominique Lang on seven counts including felony murder. Elkins' mother, 36-year-old Karimah Elkins, and sister, 19-year-old Sabrina Elkins, were charged with trying to dispose of the gun in a saltwater pond.

DOCUMENT: Read the full indictment of 5 in killing of toddler

The indictment also charges Elkins with trying to rob a man at gunpoint March 11 and shooting the victim in the arm.

The shootings of the Brunswick mother and her 1-year-old son last week in which the boy was killed were random, Glynn County Police Chief Matt Doering said at a news conference Wednesday.

Doering said it had been a judgment call about releasing the information that the location and victims of the shootings were random, but he said investigators are now comfortable in revealing that.Karimah, Katrina and Sabrina Elkins

(Karimah, Katrina and Sabrina Elkins pictured, right)

"This location was random and the victim was random we believe and so far, the evidence we have does not lend itself to any gang-related charges," said Doering.

Elkins' defense attorney, Kevin Gough, had strong words during a Wednesday evening media conference.

"We are deeply disappointed and troubled that this case was rushed before a grand jury prematurely," said Gough. "We are confident that numerous witnesses have yet to be interviewed and test results remain pending."

With both teens behind bars, Gough said he looks forward to proving his client's innocence.

"He is not an animal, and is innocent," said Gough.

13-month-old Antonio Santiago

Doering acknowledged that Sherry West, the slain child's mother who was shot, has told media outlets the shootings were the result of a robbery attempt. Doering said investigators are exploring that.

West said she was pushing her son in a stroller Thursday morning when the suspects approached and asked her for money. She said she told them she didn't have any, and said Elkins shot Antonio in the head. West said he also shot her in the leg.

Doering said West "was never a suspect in my mind," and he called the crime "a true tragedy, the worst evil imaginable."

There have been no further arrests.

Doering said there is no evidence the shootings were gang-related.

"It's obvious. We've seen the Facebook pages," Doering said. "Everyone knows what's out there. That is still being explored."