Stokes was killed in a drive-by shooting at her home on Cottonwood in South Memphis last Friday.
Some neighbors told WREG they would not give police information about the murder, even if they knew who pulled the trigger.
"I hope he gets caught," Isaiah Norwood said of Stokes' killer. "I don't know who he is. If I did know, I wouldn't rat though."
Norwood lived around the corner from where 15-year-old Cateria Stokes was shot and killed while asleep in her bed last week.
"That shouldn't even happen. Police really need to be up on their job," he said. "There are people dying out here everyday."
WREG asked Armstrong where the investigation into her death stands.
"People in the neighborhood are so worried. Is there anything you can do just to give them a bit of hope about if you have any leads?" WREG asked.
Armstrong would not answer and asked for the next question.
He did however have harsh words for anyone who was not coming forward with information.
"That in itself is a crime," he said. "That's a fundamental breakdown in this society."
He promised that the department was doing all it could to get Stokes' killer off the streets, regardless of those who think like Norwood.
"We don't snitch," Norwood said. "That is how I was brought up. You tell, you die."
Police said they can't say whether Stokes' killing was gang related, connected to drug activity or in retaliation for another incident.