FORT LAUDERDALE, Fla. -- Jurors struggled to hear audio tapes Tuesday in the trial of two men accused of killing a South Florida woman with silicone injections.

Video

The Tale Of The Tapes

Prosecutors say the tapes show Mark Hawkins and Donnie Hendrix (pictured), a man living as a woman who also goes by the name of Viva, are guilty of murder. The two are accused of throwing so-called "pumping parties" where they would resculpt customer's bodies in cut-rate, illegal cosmetic procedures.

Vera Lawrence attended one of those parties and wanted to enlarge her buttocks. Prosecutors say Hendrix and Hawkins killed her with a massive dose of silicone that made its way into her bloodstream.

On the police tapes, Hendrix denies that he and Hawkins injected Lawrence. Hendrix also apparently contradicts himself on the tapes when he answers to his whereabouts and when he arrived at the Miramar apartment where Lawrence died.

The defense called the former medical examiner to testify on Tuesday. He says that one silicone injection couldn't have killed Lawrence but that years of repeated exposure would be fatal.

The defense has contended throughout the trial that Lawrence repeatedly underwent silicone injections over the course of up to five years, and says it was that behavior that caused her death.

Hendrix and Hawkins are facing third-degree murder charges.