No builders are facing criminal charges, says Ontario Police Detective Mike Macias. Rather, but they're being asked whether or not any Ontario employees has ever asked them for money or other favors to speed up the building process.

Nearly 4,000 letters were mailed this week to developers, contractors and related professionals who have done business with Ontario building officials over the past three years. One LA-based commercial developer who received the mass-mailer tells GlobeSt.com that the letter urges builders to contact Ontario officials if they've ever been asked to supply cash or gifts "beyond the scope of normal business."

The Inland Empire has been among the nation's fastest-growing regions for the past 30 years. Homebuyers were attracted to the region in the 1970s and '80s by its inexpensive housing, and the homebuilding boom was soon complemented by hundreds of new commercial real estate projects.

Ontario, which used to be known best for its small wineries and farms, is now one of the Inland Empire's largest communities. Rumors that some officials at its City Hall are crooked has been around for a long time, but substantial evidence of wrongdoing only began to surface about a year ago.

Two months ago, Ontario police walked into City Hall and arrested senior planner Albert Cruse, 41, as Cruse sat at his desk. Cruse allegedly had demanded about $12,000 in bribes from Newport Beach-based developer Simon Construction Inc.: In exchange for the money, Cruse allegedly promised to speed the company's building process and ignore some city-mandated requirements.

A Simac official, working with local authorities, secretly tape-recorded Cruse in a meeting in which the Simac exec gave Cruse a $7,000 check. Cruse has denied any wrongdoing and is free on $60,000 bond, but was recently relieved of his $66,180 city job.

Records show that Cruse is at least the fourth Ontario city employee to be charged with financial misdeeds in the past five years. Those previous problems were a factor in the police department's decision to launch this week's mailing campaign to builders, police detective Macias says.