Good Samaritans beware: A traveling con man has returned to the Bay Area, and may be only too eager to help relieve you of your money and peace of mind, according to police.

Simon Gann, one of the notorious Gann twins, returned to the attention of Menlo Park police officer Felicia Byars after his parole date arrived. "Knowing what I know about him, I double-checked," she said.

Gann violated parole by departing for areas unknown, according to police, or at least unknown until people who had the misfortune of encountering the man under one of his well-worn aliases turned to Google and unearthed a trove of newspaper stories about his past activities.

He'd been sighted in Arizona, Oregon, Washington and Las Vegas, according to Byars, who started getting telephone calls. He was allegedly up to "the exact same thing."

"The exact same thing," for Gann usually involves posing as a math savant and business tycoon who just needs a helping hand to recover from losing his passport and wallet.

In December 2010 he admitted sweet-talking a Menlo Park woman into a relationship and out of approximately $1,900 by pretending to be a millionaire MIT graduate named "Saleem Dutante" who could count cards "like Rain Man," and pleaded no contest to multiple felony charges in San Mateo County Superior Court. He was sentenced to 16 months in state prison.

From behind bars, the con man wrote two letters to the Menlo Park victim threatening to broadcast her sexual history unless she refused to take the stand. He also offered money, the district attorney's office said.

Unimpressed, the victim reported the letters to police, which earned Gann additional charges of witness tampering on top of grand theft.

Authorities had tripled his initial bail to $100,000 after discovering Gann's multiple convictions for fraud in Canada in 2009.

A penchant for ripping people off appears to run in the family. His identical twin brother, Jordan, is serving five years in Florida prison for conning a woman out of thousands of dollars by posing as an Ivy League oncologist and real estate mogul in 2008.

"They're professional con artists," Byars said. "They could convince you to give up your grandmother if they wanted to."

While it's nice to help someone out, she urged everyone to first make sure that the person asking for assistance really needs the help.

Anyone with information about Gann's activities can call the Menlo Park police department at 650-330-6300 or email FFByars@menlopark.org.