Hearing from three of a woman's 46 personalities was enough for a jury to conclude she was mentally ill and convict a man of having sex with her by taking advantage of a young, fun-loving personality.

By convicting Mark Peterson, 29, of Oshkosh, of second-degree sexual assault Thursday, the jury said the defendant knew the woman had multiple personalities and violated the state law against having sex with a mentally ill person.The Winnebago County Court jury of six men and six woman deliberated for about 61/2 hours just after Peterson testified that he did not know of the woman's mental illness when they had sex in his car June 11.

Peterson showed no emotion when the jury found him guilty after a four-day trial. He faces up to 10 years in prison and $10,000 in fines at his sentencing Dec. 10.

The defendant remained free on a $5,000 signature bond. Defense lawyer Edward J. Salzsieder said he had not decided whether to appeal the case.

Peterson acknowledged having sex with the 27-year-old woman, whose identity has been withheld, but said he did not know about her multiple personality disorder until afterward, when he talked with neighbors. He testified he had sexual relations with a personality known as "Jennifer".

In closing arguments, Winnebago County District Attorney John Paulus said Peterson "intentionally manipulated a person."

"Who really speaks for the mentally ill in this society?" Paulus said. "What (Peterson) did was to manipulate that mental illness." Citing earlier testimony, he said the defendant knew of the illness and "he worked it to his own sexual advantage."