Bill and Lorraine Currier were last seen when they left their Burlington jobs on June 8, 2011.
Investigators later determined that their home had been entered forcibly, and there was evidence of a possible struggle. Their car was stolen and recovered two days later about three-quarters of a mile away.
Police believe 50-year-old Bill Currier and his 55-year-old wife Lorraine were victims of foul play.
For the last two months federal authorities have been searching a Coventry landfill for evidence in the case. In April police searched vacant lot in Essex.
Authorities are holding a press conference on Friday to provide an update on the search.