GARLAND, TEXAS: A 17-year-old Texas girl who was the subject of an Amber Alert on Friday, August 1, has been charged with murder.

Natalie Navarro was arrested for killing Arturo Pena, 21, just three days after he was found fatally shot inside a vehicle in Garland, Texas.

Police also identified 21-year-old Yordy Martinez as another suspect in the murder case.

The authorities immediately listed Martinez as a suspect in Navarro's disappearance when the Amber Alert was issued on Friday after police received information of her sudden disappearance under 'suspicious circumstances' from an apartment complex in east Dallas at around 1.30 am.

Where is Yordy Martinez?

A warrant for murder was issued for Navarro and Martinez at the time of the Amber Alert, but Martinez is feared to have escaped scot-free across the US-Mexico border.

Not many details have been provided by the authorities regarding the circumstances that led to Navarro's disappearance and arrest.

The police are still "trying to figure out exactly" how the three individuals knew each other.

On August 29 at around 10 am, police found Pena inside his car after they received reports of a person being discovered unconscious. Later, it was determined that the victim was shot to death.

According to Fox 4, Pena was reported missing to the Dallas Police Department two days ago.

How did the police arrest Natalie Navarro?

Police traced the suspects during their investigation and obtained warrants after identifying them as persons of interest in the case.

However, the incident took an abrupt turn when Navarro, who was not charged at the time, became the focus of the Amber Alert.

According to the authorities, the circumstances around her disappearance met the conditions for the warning, but they have not elaborated further on the circumstances.

She was found and apprehended by police within an hour. According to police, she was "safe and in custody."

A brief description of the suspect at large

Martinez, who police initially listed as a suspect in the Amber Alert, is considered to have fled in a dark gray, four-door car.

There are concerns that he might have escaped to Mexico. According to the authorities, the 21-year-old is missing a front tooth and has a rap sheet that includes a felony indictment for allegedly shooting a gun into a house in Garland last November.

Why was Pena killed?

The exact reason for the murder of Pena has not yet been revealed.

"There’s a lot of stuff going out, we’ve collected a lot of evidence, so we’re trying to process everything right now", said Lt Richard Maldonado of the Garland Police Department.