Dallas — The police force partner of former Dallas police officer Amber Guyger acknowledged that they had a sexual relationship and exchanged sexually explicit text messages and photos with her the day she shot Botham Jean. However, Martin Rivera denied making plans to rendezvous with Guyger later that night, as prosecutors suggest.

Prosecutors contend Guyger was distracted by a telephone conversation with Rivera when she mistook Jean's apartment for hers and entered, believed him to be an intruder and shot him.

Fired Dallas Police Officer Amber Guyger listens as her attorneys make arguments during her murder trial, Monday, Sept. 23, 2019, in Dallas. Tom Fox / AP

Prosecutors questioned Rivera extensively about a 16-minute phone conversation he had with Guyger as she headed to her apartment that night in September 2018. Asked what it was about, he said he believes it was mostly about police work but his memory of the call was hazy. Again, however, he denied that it involved plans to see Guyger later that evening.

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Prosecutors said that after Guyger shot Jean, she deleted the logs of her text exchanges with Rivera from her cellphone. Rivera said he didn't know why she had done this but acknowledged having done the same as well.

Policeman Martin Rivera, right, looks as Assistant District Attorney Jason Hermus shows him his texts and Snapchat records as he testifies on the witness stand, Monday, Sept. 23, 2019, in Dallas. Tom Fox / AP

CBS DFW reports that those racy messages have been recovered and Rivera then testified about the messages.

Prosecutor Jason Hermus: "Would you send provocative photographs of yourself to Amber Guyger?"

Corporal Rivera: "Uh, yes."

One text from Guyger read, "Wanna touch?" around 9:30 the night of the deadly shooting.

At 10:02 p.m., Rivera received a text from Guyger, "I need you. Hurry."

At 10:03 p.m., Guyger texted Rivera, "I *ucked up."

Prosecutor said Guyger typed those last messages while she was on the phone with 911 saying she's shot Jean.

Jean family attorney Daryl Washington called the messages revealing.

"At the time that Botham was struggling to take his very last breath, we saw a police officer who was more concerned about herself and was sending off text messages," Washington said.

Guyger was off duty but still in uniform when she shot Jean. She told investigators that after a 15-hour shift she parked on the fourth floor of the complex's garage - rather than the third floor, where she lived - and found the apartment's door ajar.

Three days later, Guyger was arrested for manslaughter. She was subsequently fired from the Dallas Police Department and charged by a grand jury .

The jury will have to decide whether Guyger committed murder, a lesser offense such as manslaughter or criminally negligent homicide, or no crime at all.