Born in California, Castle came to Massachusetts in the summer of 1983 to visit her grandmother while her parents were going through a divorce. She decided to stay and finish high school in New England. At the age of 15, Castle joined an after-school police explorer group for teens and was hooked.
"I learned a lot about what police officers do," said Castle. "I wanted to be a cop."
After high school she earned her associate's degree in criminal justice at Quinsigamond Community College in Worcester, juggling numerous jobs during the two years.
Castle worked for a retired police officer as a private investigator, primarily following married men to confirm their infidelity, while she held down an 11 p.m. to 7 a.m. shift at Worcester City Hospital as a security guard, where she did everything from moving bodies in the morgue to restraining belligerent patients.
"When I finished at 7 a.m. I would go home, change my clothes, and go to class," said Castle. "On a good day, I'd get four hours of sleep."
After college, in the late 1980s, Castle joined another private investigation firm, where one of her assignments took her to a local manufacturer, where she was asked to investigate complaints about the human resources director and suspicions that assembly line employees were involved with drugs.
"When I would go into these companies, I would have to get a [legitimate] job," said Castle. She spent six months working a wave solder machine, making circuit boards, and socializing with employees after work at a local pub. Castle said one employee would smuggle a flask of liquor to work and another sold cocaine.
"Understand that I have never done drugs, so not only did I have to befriend [the dealers] and buy drugs, I had to act like I knew what I was talking about," said Castle.
