The Honduran nationals were taken into custody last week in Houston, Texas, where they remain held without bail by immigration officials pending extradition.
They're charged with the killings of 27-year-old Alex Aguilar and 48-year-old Marcial Morales-Maldonado. The men, also from Honduras, were found bludgeoned to death on Feb. 28 at the Sterling Chase Horse Farm in Springfield.
The four worked and shared living quarters at the Burlington County farm.
CLICK HERE to follow Action News on Twitter
CLICK HERE to get Action News on your website
CLICK HERE to find Action News on Facebook