CONROE, Texas -

A teenager shot and killed steps away from a busy Walmart. An off-duty police officer pulled the trigger, killing a teenager steps away from a busy Walmart, and now the teen's father is questioning whether police acted within the law.

It's the last moments of the young man's life that are in question. Police say the officer was feared for his life when he shot the unarmed teenager. But quite frankly, the teenager's family doesn't buy it and Monday they presented their case to the public.

He died in the woods near a Conroe Walmart. Russell Rios at 19 was a shoplifting suspect, shot and killed by an off-duty Conroe police officer. At the time Conroe police told us this is what happened.

"He was struggling with the officer to the point and he was in fear for his life and at that time there was one shot fired," said Sgt. Dorcy Riddle back on Aug. 1.

But Monday on the steps of the Montgomery County courthouse, a month after the teen's death, his family and their lawyers questioned Conroe police's version of events.

"Ladies and gentlemen that is not the truth," said attorney Ryan Macleod.

Front and center was the curious point of how Russell Rios could have been shot in the back of the head if he was at the time choking the man who shot him.

"The number one thing we would like is have justice done for my son," said Rios' father.

To that end, the Rios family is asking for an independent investigation into the fatal officer-involved shooting.

"I want to know why the Conroe Police Department is conducting this investigation. This is the same agency that hired this man," said Macleod.

Had Russell Rios actually shoplifted? Should an off-duty cop have pursued him? And what really happened in those woods? The family says they deserve truthful answers and they claim they haven't gotten them yet.

"What if he would be your son? Can you step in my shoes?" Rios' father said.

Conroe's police chief tells Local 2 News, "The investigation is still ongoing. We're taking our time and doing the investigation to the fullest... In conjunction with the Montgomery County District Attorney and being assisted by the sheriff's department."