"I will light you up," a state trooper told Bland while pointing a stun gun at her. She died in police custody three days later.

Sandra Bland, whose death in police custody three days after being detained for a routine traffic stop in Texas highlighted issues of mistreatment of black people by white police officers, recorded her own arrest on her cellphone.

The newly released footage from July 10, 2015, shows a Texas state trooper telling Bland he will "drag" her out of the car as she questions why she is being apprehended.

State Trooper Brian Encinia then pulls out a stun gun and points it at Bland.

"And then you’re going to stun me?" asked Bland. "I will light you up," he replied. The 39-second video of the 2015 arrest was published Monday by an investigative news program on the news station WFAA, and is the first time Bland's video has been made public.

"Open up the case, period," her sister Shante Needham told WFAA after seeing the video for the first time.

Bland, 28, died in custody on July 13, 2015. Her death was ruled a suicide.

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