TEMECULA - If sleuths - both professionals and would-be detectives - are asked to solve a faux-murder mystery, odds are Valerie Zwirn will be on the case.

Organizers of the Erle Stanley Gardner Mystery Weekend, which concludes today, expected the Cerritos resident to be present and sign on as a gumshoe to solve this year's whodunit. Predictably, she is in Temecula - Gardner's hometown from 1937-70 - this weekend working the case.

Sitting at a small table at the Old Town Temecula Community Theater's Mercantile room Saturday, Zwirn concisely but sharply probed a panel of actors portraying characters close to the murder victim. She extracted clues - some helpful, others not - to help solve the case during a 10-minute interview session. There were four sessions conducted Saturday.

Zwirn is an expert among the amateur sleuths, many of whom attempt to solve whodunits just once a year - during Old Town's mystery weekend.

Each year, she said, Zwirn enrolls in at least one mystery cruise, in addition to the dinners in which she participates. Even without a sleuth's characteristic prop - a magnifying glass - she looks the part with her big block rectangular glasses. Impressive, considering she worked in the Los Angeles County Office of Education before retiring.

"I'm a big Perry Mason fan," she said, referring to the iconic fictional character created by Gardner. "I love trying to solve cases; trying to outwit the murderer and the detectives."

It certainly helps Zwirn that the mysteries "are based on Perry Mason with a twist - so you can't go to the Internet and figure it out," said amateur gumshoe Martin Luna.

Other sleuths are less clinical than Zwirn - even "clueless."

"Clueless" is the name of the Luna family team, which also attended the 12:30 p.m. interview session.

"We're pretty much walking in a fog," joked Luna, 50.

Not quite.

Last year, Luna and his two children tied for first-place, but their last name was not pulled out of a hat to determine the winner.

After the 12:30 session, the three of them continued to collect clues, this time from shops along or near Old Town Front Street.

"Some (shop owners) make it tough: They'll put it in the cooler behind the six-packs of soda," Luna said. "Others, they put it right out in front."

J. Gordon Specialty Store on 5th Street, which sells model trains, barely concealed its clues. If sleuths asked for a clue, the store's owners would reveal them from a jar near the register.

"One time, we kind of hid clues and people starting rummaging through things," said owner John Gordon, 65. "There are breakables here."

Winners of this year's murder mystery will be announced at 4 p.m. today. Most of the events are being held at the Old Town Temecula Community Theater.

For more information, log on to www.temeculacalifornia.com.

Contact staff writer Brian Eckhouse at (951) 676-4315, Ext. 2626, or beckhouse@californian.com.