AUSTIN -- Three people have been charged after a fatal shooting in East Austin on April 19 that developed over an alleged robbery scheme, police said.

Police responded to the call at 6:28 p.m. Thursday at 1148 Poquito Street. Once police arrived, the officer found two males on the ground, one with a gunshot wound to the chest, the other with a gunshot wound to the arm. Police said EMS arrived shortly after and transported both men to Dell Seton Medical Center.

The victims were later identified as Keeven Darrall Cubit, 26, and Tyquell Labyrant Douglas, 17. Cubit was pronounced dead at 6:58 p.m.

Police said a witness observed a Hispanic male walk to the scene on Poquito Street and pick up a pistol from the ground where the shooting occurred. Police later identified this suspect as Jose Luis Vargas-Martinez, 18, who was later detained and found to be in possession of a black Rossi .38 caliber revolver handgun.

Once taken into custody, police said that Vargas-Martinez stated he acted as the lookout for an aggravated robbery, which was planned by his friend, "Alex." He reported that Alex had been planning the robbery for three days because he needed money. Alex had reportedly told Vargas-Martinez to get two guns and meet him, which he did, with the plan to rob the victims of a pound of marijuana.

According to Vargas-Martinez, the victims were in a Black Dodge Avenger. When they arrived, Cubit and Douglas got into the car. Vargas-Martinez said he heard several gunshots fired from the Avenger as the vehicle drove off. Vargas-Martinez reported he saw the victims running away from the vehicle yelling that they had been shot.

According to police, Vargas-Martinez was later shown a photograph of Alexander Moux, as they had been involved in a prior incident with the APD, whom he identified as Alex.

After speaking with Moux on Friday, police said he reported that he initiated contact with someone he knew from Mabel Davis Skate Park with intent to rob him. This subject was identified as a 16-year-old juvenile.

Police said Moux planned to rob the subject of $130, but when he saw more than one person inside the Avenger, he changed his mind and had Cubit and Douglas commit the aggravated robbery.

Moux later consented to have his cell phone searched, where police found evidence confirming the arrangement to meet up on Poquito Street to buy marijuana and "lean" from the juvenile.

Police said the juvenile and Charles Jerome Postell, 22, agreed to meet with the APD to provide their account of the aggravated robbery with a deadly weapon. The juvenile stated that he agreed to meet with Moux to sell him $260 of weed and $130 of lean, and that Postell drove him to meet up in Postell's Avenger.

The juvenile stated that Moux approached him soon after they parked on Poquito Street and told him that his "connect" was going to talk to him. The "connect" was later identified as Cubit.

Police said Cubit walked to the driver's side rear passenger door of the car and sat halfway inside and tried to snatch the $130 from the juvenile, but failed. At this point, police said Cubit then brandished a black revolver and pointed it at the juvenile, when Postell pulled a second handgun from under his leg and pointed it at Cubit. Police said Cubit then pointed his gun at Postell and began to get out of the vehicle when Postell fired at him. Then, the juvenile reported that Douglas opened his door and aggressively tried to pull him out of the vehicle when Postell turned his revolver on Douglas and fired.

Upon meeting with Postell, police said he reacted out of fear for their safety and described it as a "life or death "situation. Police said Postell stated, "I did what I had to do" when he fired the shots.

Moux, Vargas-Martinez and Douglas were charged with aggravated robbery, a first-degree felony.