About Us
Mahoney & Sons Investigations, Inc. is a full service, licensed and insured private investigation firm based out of Contra Costa County, California. We are dedicated professionals committed to providing a comprehensive investigation with integrity for attorney’s, companies, and private persons.
Knowledge is power
We at Mahoney & Sons Believe You Deserve Knowledge.
No matter what aspect of modern life you're approaching, without knowledge of the subject you're at a clear disadvantage. Ranging from workplace investigations to matters of the heart, Mark Mahoney has your back.
Sub-Rosa
(Worker’s Comp Fraud)
Richard Lyons Corriea
Attorney-at-Law; Former Commander of SFPD
"I have known and worked with Mark Mahoney for more than three decades. I know him to be a superlative experienced investigator, dedicated and reliable. He is tenacious, thorough and ethical. I’m delighted to recommend Mark Mahoney for all your private investigation needs."
Michael Biel
Deputy Chief of Police, SFPD (Retired)
"Mark Mahoney provided honorable and dedicated service to the city of San Francisco and it's citizens. His exemplary and distinguished career spanned over thirty years and culminated with his retirement as a Captain of Police. Mark has highly developed skills and broad experience in investigations. I have every confidence in his abilities and do not hesitate to recommend him as a private investigator."
Kitt Crenshaw Sr.
Retired Commander Operations , SFPD
I met Mark Mahoney in the mid 1980’s, Mark was assigned to my Investigative narcotic’s team of the San Francisco Police Dept. Mark worked in several capacities, Undercover Buyer and Investigator. Mark excelled in every phase of investigative street work. Mark’s enthusiasm and exemplary style were his calling card. Mark often demonstrated his exceptional ability to analyze and evaluate complex case work. I have known Mark Mahoney for over Thirty Years and consider him a friend an outstanding individual and professional investigator.
Thomas G. F. Del Beccaro, Esq.
Del Beccaro, Hornsby & Blake
"I met Mark Mahoney when he was a Captain with the San Francisco Police Department. Once he became a California licensed Private Investigator, I’ve had no trouble hiring him to conduct investigations on numerous cases. I’ve found that Mark’s expeditious work ethic is always thorough and professional. I would highly recommend Mahoney & Sons Investigations, Inc."