AUSTIN (KXAN) — Austin Police are searching for a man who they believe robbed a store on Montopolis Drive at gunpoint. Detectives have identified 18-year-old Ernesto Barrientes as the suspect, thanks to some detective work by the victims.

Dustin Kelly, an employee at the store, described the robbery as frightening and maddening.

“I was on my phone, and next thing I know I hear, ‘Get up,’ and I’m like, ‘Excuse me?’ And I look up and it’s a guy there with a gun, a huge magazine on the gun, and I’m just like, ‘Oh, wow. This is real,’ and he’s like, ‘Get up! Get up, or I’ll shoot you!'”

Kelly says he was in a back room before his shift started. He says the suspect walked him out to the front of the store.

“And I just see my coworkers on the ground, face down. I’m like, ‘Damnit, this is really real,’ and then he told me, ‘Get on the ground! Get on the ground!”

Kelly recalls that as the man was taking money out of the cash register, he saw an opportunity to run out, and yell for help. When detectives got there, Kelly says they dusted for fingerprints and looked at surveillance footage.

After a day went by, however, Kelly wanted to help speed up the process. He analyzed the security footage himself. Kelly says in it, the suspect’s face was covered, but he had a unique tattoo on his arm, with gang letters.

“I just typed in the name, the name of the gang. He was the first person to pop up,” Kelly said.

The store employee found two social media accounts for Barrientes and turned them over to police.

An arrest warrant says detectives quickly figured out that Kelly had indeed tracked down their suspect. It says Barrientes was already listed as a known gang member in APD’s data base.

With detectives fighting heavy case loads, Austin Police say assistance from people, like Kelly, is of great help.

“With any type of offense, time is of the essence,” said APD officer Destiny Silva. “So if we do have that information, it’s already prepared and readily available, it does assist greatly with an investigation.”

APD stresses, however, that people are encouraged to help detectives within reason. Gathering security footage and details is helpful, but officers warn the public to never follow a suspect or put oneself in danger.