only 14 years old, visiting relatives in mississippi when he was accused of whistling at a white woman, then kidnapped, beaten, brutally murdered. his killers never convicted, his mother insisting on an open casket so the world could see what had been done to her child. reverend wheeler parker, the oldest child seen with till is emmett's cousin. parker is the last living relative to witness the abduction. what do you remember about that moment >> i remember hearing the men talk about 2:30 in the morning i said, we getting ready to die, these people are going to kill us >> reporter: today, reverend parker was at the white house to bear witness once again, this time history being made in his cousin's name. >> i just signed into law the emmett till anti-lynching act. >> reporter: president biden signed the first law that makes lynching a federal hate crime, passed unanimously in the senate this month. >> racial hate isn't an old problem, it is a persistent problem.