The suspected serial killer graduated with a degree in architectural technology from the New York Institute of Technology before reportedly working his first internship at Greer Construction corporation in Freeport.
He started his own company, RH Consultants and Associates, in 1994 in Manhattan - with big-name clients, including Target, Nike, Catholic Charities and Cipriani, according to the company website.
The website also boasts of the team's more than two decades of experience working with the New York City Building Codes and all major city agencies.
State records show Heuermann's architecture license is in good standing.
In an older interview posted by Bonjour Realty that News 12 has permission to share, Heuermann appears jovial - kidding about the weather on a gloomy day similar to the day of his arrest.
VIDEO: Courtesy of Bonjour Realty
He goes on to brag about his prowess trouble-shooting negotiations with the New York City Building Department on behalf of his high-profile clients.
A search of his financial records shows a trail of federal tax liens dating more than a decade - one of them for over $100,000.
Records show he married his first wife, Elizabeth, in 1990. They divorced, and he has since remarried. His daughter reportedly works at her father's firm.