In the first chapter of Margaret Atwood's Blind Assassin, the narrator recalls her sister Laura's suicide. Laura was wearing white gloves when she driver her car off a bridge --
"The white gloves: a Pontius Pilate gesture. She was washing her hands of me. Of all of us"
What do the white gloves means? And what's the link to Pontius Pilate?
I have Googled but not much luck.