A hotel employee testified Thursday that he tried to stop a Houston-area woman from driving over her husband in the parking lot.

But Vance Smiros watched helplessly as dentist Clara Harris hit her orthodontist husband, David Harris, three times, according to his testimony.

Smiros testified he heard David Harris yell to his wife: "It's over! It's over! It's over!"

Smiros said that Clara Harris calmly got into her car with her 16-year-old stepdaughter, Lindsey.

Smiros banged on the car's trunk and yelled: "Stop! Stop! You're going to hurt someone."

He said that's when Clara Harris hit her husband.

Smiros said Lindsey Harris then told her stepmother: "You killed my dad."

"We saw that there was an altercation and then she took off and she basically ran over the gentleman," Smiros told News2Houston. "I would imagine that if you find your husband cheating, I'm sure you'd be angry. She was angry at the time."

Clara Harris, 44, is charged with murdering her orthodontist husband, David Harris, 44, on the night of July 24 after a confrontation with him and his alleged mistress, Gail Bridges, in the lobby of the Hilton Nasa Clear Lake, Nasa Road 1, in Nassau Bay.

Another hotel employee testified about the fight between Clara Harris and her husband's alleged mistress.

"I saw Clara Harris pulling and screaming at Gail Bridges. She punched her with her closed fist in the face, knocked her to the ground and then punched her in the face again," Garrett Clark testified.

Clark said that David Harris never intervened.

"Gail was a mess afterwards. She was upset and scared for her life, shaking, trembling. She couldn't complete a sentence," Clark said.

Clark then escorted Bridges outside to her car with David Harris behind them. He said that he heard a car revving up and coming at them. It hit Clark, scraped a car and then hit David Harris, according to Clark.

"I looked up at David. He had bulging eyes, a terrified look. The defendant hit David and came to a complete stop. He flew about 25 to 30 feet," Clark testified.

He said that Clara Harris drove over the body, in circles, three times, then reversed and ran over him again.

In cross-examination, Parnham found several inconsistencies in Clark's story, News2Houston reported.

Opening statements Thursday morning set the tone for the high-publicity trial.

"She turned her $70,000 vehicle into a 4,000-pound murder weapon," Harris County assistant prosecutor Mia Magness told jurors in opening statements. "The evidence will show you she ... hit him again and again and again."

In his opening statement, defense attorney George Parnham described Harris as a woman who only wanted to keep her family together and who "loses it" after discovering husband David Harris with his mistress at the same hotel where he and Clara Harris were married.

"The elevator door opens and out steps David and Gail Thompson Bridges," Parnham said. "David comes over, a martial arts aficionado, pulls his wife and throws her to the floor."

"The defendant attacked Gail Bridges there in the lobby," Magness said. "David Harris at that point told his wife it's over."

Magness said Clara Harris was so obsessed with keeping her husband she hired a private investigator to "get some dirt" on Bridges.

She also gave her husband an ultimatum and when he chose Bridges, Clara Harris got into her car and decided to run him down, Magness said.

"Clara Harris got mad," Magness said. "She intentionally and knowingly hit David Harris with her vehicle and he died as a result. And the bottom line folks is that's murder."