The Director of Engineering at On Guard Security Systems Inc. in Modesto, California, is Roy Bartholomew Sonora CA. Mr. Bartholomew is the seventh of eight children born to French-speaking Cajun parents, and he was raised in the San Francisco Bay Area.

After 35 years in the engineering industry, Roy Bartholomew Sonora CA has amassed a select and in-demand skill set and profitable partnerships with local and national business owners. He is now the proprietor of By Referral Only Electric.

Mr. Roy Bartholomew Sonora CA is well-known in the engineering community for his High-Quality Engineering, Design Work, and Consulting for Biodomes and other engineered ecosystems, which he performs in addition to his full-time career and entrepreneurial endeavors. Present-day Mr. Bartholomew is a married father of one from Northern California.