The former death row inmates describe it in their lawsuit ... and the gunmen convicted of bigotry-fueled massacres inside a Charleston, South Carolina, church and a Pittsburgh synagogue.

Moises Mendoza used his last words to apologize to Rachelle Tolleson's family before he was executed for her 2004 murder ...

Mendoza was sentenced to death row for the murder of 20-year-old Rachelle ... Mendoza told police he let himself inside Tolleson's house through a back door that night, per court documents.