"A former coworker told The Post that suspected serial murderer Rex Heuermann, 59, once took time off from his job as a Manhattan architect to install a concrete-lined vault at his family’s Long Island house.
It’s not clear if that basement compartment is the one cops suspect could have been a killing chamber or whether it is possibly the space previously reported to hold Heuermann’s up to 300 guns.
But 'it’s not just a hidden room — it’s a serious vault,' the ex-colleague said.
'It had a huge heavy-duty safe door. He went and poured new concrete walls, massive amount of concrete to encase this room.'
'It was maybe 2 or 3 feet thick,'
the former coworker said."
Cops have reportedly found a soundproof room in the basement of accused Gilgo Beach serial killer Rex Heuermann’s home where they believe at least one woman may have been killed.
nypost.com