At the center of the uproar over a Google project that scooped up personal data from potentially millions of unsuspecting people is the company software engineer who wrote the code.

Google has declined to identify the engineer, as has the Federal Communications Commission. The F.C.C. recently closed its 17-month inquiry into the project, Street View, with a finding that Google broke no laws but had obstructed its investigation.

The agency also said it was unable to resolve all the issues it was considering because the engineer — whom it referred to in its report on the inquiry as Engineer Doe — cited his Fifth Amendment right and declined to talk.

Now a former state investigator involved in another inquiry into Street View has identified Engineer Doe. The former investigator said he was Marius Milner, a programmer with a background in telecommunications who is highly regarded in the field of Wi-Fi networking, essential to the project.