British tourist Sheila Sillery-Walsh, 48, took a snap of one of the prison windows and was amazed to see the image of a girl when she looked down at her phone after taking the picture.
Speaking to the Daily Mail, Ms Sillery-Walsh said that once she’d spotted the girl, she could think of nothing else.
“When I glanced at the photo on my mobile, I saw this dark female figure in the picture. I looked at the window again and there was no one in the room,” she said.
“From that point onwards, I wasn’t interested in the Alcatraz tour anymore. I just kept looking at the picture over and over again!”
Image credit: Twitter/America’s Most Haunted