Professional Investigative Services Built on Trust and Expertise

Aerial shot of the Downtown District overlooking the cityscape of Los Angeles at sunset.

L4 Investigations is led by licensed investigator David Lis. Mr. Lis has over 25 years in law enforcement and security operations and retired as the Investigations Commander for a suburban Chicago law enforcement agency. Other assignments include serving on a Drug Enforcement Administration Task Force and a multi jurisdictional SWAT Team. Drawing on these experiences, I am able deliver private investigation services that prioritize discretion and thoroughness. My mission is to provide individuals and businesses with reliable and effective investigative solutions, tailored to their unique needs. I am committed to building lasting partnerships through clear communication and proven results, whether you require service of process, surveillance, or other investigative pursuits.