In Florida, Jorge Diaz-Johnston was recently found dead in a Jackson County landfill, ABC News reported.
Diaz-Johnston, 54, was reported missing on Jan. 3 near his workplace and police are investigating his death as a homicide, according to a police spokesperson.
Diaz-Johnston was one of the plaintiffs in a 2014 lawsuit against the Miami-Dade county clerk's office, which refused to issue same-sex marriage licenses. The couples eventually prevailed.
Diaz-Johnston was the brother of Manny Diaz, the former Miami mayor and current chair of the Florida Democratic Party.
In a tweet, Equality Florida posted, "We are heartbroken to learn of the death of Jorge. He and his husband Don were two of the brave plaintiffs who took on Florida's anti-gay marriage ban and helped win marriage equality for all Floridians. Our deepest condolences to Don and Jorge's extended family."