"We are not going home until we get justice," she said.
Her family filed a wrongful death lawsuit against the county and Cameron Brewer, the former Harris County Sheriff deputy who killed her brother.
Dashcam video from Brewer's patrol car shows Danny Ray Thomas with his pants down approaching Brewer.
Marketta said what the video doesn't show is the pain her brother was holding deep down after his kids were drowned in a bathtub by their mother, Sheborah Thomas, in 2016.
"He was depressed about his kids. He was going through something, as we all go through, and we all deal with stress and depression differently," said Marketta Thomas.
"I told him, 'you have to move on with life,'" said Donald Woods, Thomas' father.
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Thomas didn't know how to move on. The family never thought it would come to this.
"I don't have my best friend. I'm used to him calling every day," said Marketta. "When you don't get those phone calls, it's a (painful) reminder."
Thomas' oldest daughter Raynell is now getting ready to graduate from Summer Creek High.
"I wanted him to be there, but now he can't be there," Raynell said.
She imagines him in heaven looking down on her, which is why she took a picture of her staring up at the clouds with a picture of her dad in the sky.
Thomas' shooting death has not been easy on anyone.
"It ain't real to me. I'm used to him calling me," said Woods.
Brewer is no longer working for HCSO. An internal investigation showed he did not properly follow the sheriff's office's use of force policy.
The family is now waiting to see if Brewer will face any charges.
"I don't have fear (anymore). My biggest fear was losing (my brother)," she said.
The Harris County D.A.'s office provided the following statement:
Civil Rights Division prosecutors are reviewing all the known evidence in Danny Thomas's death. Upon completion of their review, all the evidence will be presented to a grand jury to determine if criminal charges are warranted.
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