MIAMI -

Testimony continued Wednesday in the murder trial of Aventura real estate developer Adam Kaufman, who is accused of killing his wife in the bathroom of their home in 2007.

The prosecution brought in a physics expert to prove that the defense's claim, that Lina Kaufman died when she hit her neck on a magazine rack after collapsing in the bathroom, could not have happened.

In dramatic testimony, a computer stimulation showed a figure, presumed to be Lina Kaufman, sitting on a toilet, falling forward and hitting her head and face -- not her -- neck on the magazine rack.

"There was no configuration that we could find where the dominant impact was on the neck. It was always on the face and the chin and head, head and the chin," said physics expert, Dr. James Ipser.

The defense wasted no time going after the University of Florida physics professor's credibility. Kaufman's attorney mimicked a falling motion, saying it is possible to fall forward without the head leaning in.

The professor, however, disagreed.

The defense lawyer then accused the professor of looking at the prosecutor and laughing.

"Is this a joke, sir?" he asks. My client is on trial here for his life. I object to this witness looking at the state and laughing, your Honor."

The prosecution was expected to wrap up their case Thursday afternoon and then the defense will take the stand. Their first witness is expected to be Lina Kaufman's mother, who will testify on behalf of Adam Kaufman.