Hesitated to post this, but FamilySearch.org is very much open source. It's all out there.
Family Search results (open source) for Stefan (A.) Halper, date of birth 04 June 1944
Residence: Great Falls, Virginia 22066 from 29 June 1977 to 10 Jan 2009
Residence: Alexandria, Virginia 22314 as of 01 May 1995
Residence: Captiva Island, Florida 33924 as of 01 Apr 2001, possible relative Lezlee Halper
Residence: Pineland, Florida 33925 as of 01 May 2001
Residence: Sterling, Virginia 20165 from 01 Dec 2004 to 06 Aug 2008
Residence: Bloomfield, New Jersey 07003 from 29 Oct 2007 to 01 Jan 2009
Possible relatives: Elizabeth B Halper, Lezlee Brown Halper, Marin Halper, Sibyl C Halper, V H Halper, V Halper
United States Public Records, 1970-2009," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:KTKM-CVY : 23 May 2014), Stefan A Halper, Residence, Bloomfield, New Jersey, United States; a third party aggregator of publicly available information.
NOTE TO DIGGERS
There is another, apparently German Stefan Halper out there. He is significantly younger. Check estimated dates of birth to confirm.
For further digging, some U.S. counties have real estate tax information available online, but many don't. Very useful tool to find out who lived at a given address, and can confirm when a person owned the property over a period of time.
Genealogyfag will keep digging.