A physician's assistant testified Wednesday in the preliminary hearing against a San Francisco man accused of assuming his identity and using it to illegally perform medical procedures on several victims while also sexually assaulting some of them.

Carlos Guzmangarza, 49, allegedly took on the identity of Carlos Guzman and operated Derma Clinic, a clinic in the city's Mission District where he performed various procedures on nine women, including liposuction, facelifts and lip and buttock augmentations, prosecutors said.

Guzmangarza was arrested last December and faces multiple felony counts including rape, sexual battery, assault, practicing medicine without a license, false impersonation and grand theft.

The real Carlos Guzman, a physician's assistant from Fresno, testified today in the hearing on whether Guzmangarza should stand trial on the various charges.

Guzman said he had been unaware of his alleged impersonator and that as a physician's assistant, he was only authorized to do minor surgical procedures, not the extensive work allegedly done by Guzmangarza that left some victims with infections and other problems.

Guzmangarza also allegedly purported to be a doctor to some patients, something Guzman said he would never do, even when a patient refers to him as such.

"I always correct them because that's a different level of responsibility," he said.

The preliminary hearing, which continued this afternoon, has taken place over several days and included testimony from some of the alleged victims.

One victim testified Tuesday that Guzmangarza was smoking during a buttock augmentation that she had paid him $5,000 for and that he sexually assaulted her after injecting her with various substances.

In another incident, prosecutors have said Guzmangarza performed liposuction on a woman, then later came to her house and flushed pounds of her fat down the toilet. The women's abdomen then became infected and required additional treatment.

Guzmangarza remains in custody on $1 million bail and could face more than 30 years in prison if convicted on all counts.