The incarcerated individual is likely to have become part of a sadomasochistic fantasy for many of these women, given how popular true-crime shows are and how accessible the offenders are, Katherine Pier, a psychiatrist on the faculty at the University of California at San Francisco, told The Washington Post.

“It’s a way of flirting with danger while risking nothing,” said Pier, who has worked with felons. “The women writing killers are often victims of abuse and gravitate toward aggressors. Getting involved with a man behind bars puts them in positions of control. These women will most likely never have the chance to meet the man they’re pursuing. And if they did, they’d be protected by the prison system.”

Sheila Isenberg, author of “Women Who Love Men Who Kill,” echoed Pier.

It was less about chasing celebrity or being with a notorious killer, Isenberg said. Being in love with a man behind bars is exciting. “You don’t know what’s going to happen. There’s always an adrenaline rush.”