UPDATED | May 18, 2015 12:30 PM

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DALLAS (CBSDFW.COM) – The murder trial is underway for the Balch Springs man accused of killing Deanna Cook.

Cook is the North Texas woman whose physical attack and murder was recorded during a 911 call that she had placed for help. The call was not deemed an emergency or given priority and officers didn’t arrive at her home for some 50 minutes.

Officers knocked on Cook’s door and after getting no response left the scene. The 32-year-old woman lay dead inside the house. Her family discovered her body two days later.

Monday there was powerful testimony in the murder trial of Cook’s ex-husband, Delvecchio Patrick. Cook’s mother, Vickie, testified that she had warned her daughter about Patrick when the two started spending time together again.

Vickie Cook, mother of murdered 911 caller Deanna Cook, testifies. (credit: CBSDFW.COM)

Vickie Cook, mother of murdered 911 caller Deanna Cook, testifies. (credit: CBSDFW.COM)

Vickie Cook testified that she could not make contact with her daughter by phone or on Facebook for days, in August of 2012. She explained that when her daughter failed to show up for church on Sunday, she and her granddaughters went to her home and saw water running out of the garage.

On the stand, Vickie Cook recounted how, after forcing her way into the house, she found her daughter’s body. “I turned and I went to the bathroom,” she said sobbing. “And I looked, I looked to my right and then I looked to my left and I saw like a shadow, a shadow behind the curtain. And I started screaming ‘cause it was her and the water was still running… the water was still running. And I just said, ‘He killed her! He said he was gonna do it and he did it, he did it!’”

Cook’s family has been waiting more than two-and-a-half years for Patrick’s trial. What has happened since Cook’s mishandled August 17, 2012 call for help is a change to Dallas’ 911 system. The Dallas Police Department has created a new classification for call-takers and dispatchers to use when relaying reports to officers in the field. The new classification is for calls involving serious bodily injury or death and lists the calls as highest priority.

(credit: Cook family)

(credit: Cook family)

For nine minutes, during Deanna Cook’s fateful 911 call, you can hear the sounds of a struggle and a woman screaming. “Help. Please. Stop it, Red,” cried Cook. You can graphically hear Cook literally being choked to death.

When the 911 call was played for the jury on Monday several of Cook’s relatives had to be escorted from the courtroom because their cries were disturbing testimony.

Cook’s sister, Karletha Cook-Gundy, said, “It’s tragic and I don’t think she deserved that. I don’t think she deserved to die the way she died and that’s just my opinion of it. I think that as a family we just deserve more answers than what we’re getting.”

(credit: CBSDFW.COM)

(credit: CBSDFW.COM)

During testimony Monday, one of the paramedics who responded to Vickie Cook’s 911 call told the jury they found Deanna Cook floating face-down in the bathtub. The first-responder said Cook’s body was bloated and that there was no lifesaving action that could be taken.

If convicted Delvecchio Patrick, 38, faces up to life in prison.

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