From Inside the Grey House:
“All I know is that it was a woman.”
Natalia thought about it as she started walking a few steps. “Judith left before Vincent came to save me. If she shot me, there’s no telling what she used. She found a way to add various poisons to her bullets. She spent years perfecting the process. I have no idea how she did it. Chemistry wasn’t really my thing.”
Lilly frowned as they slowly continued to walk to the other bathroom. “Was she a Slayer?”
“She was.”