Willows worked as an exotic dancer on the Strip in her early 20s while going to college. A young filed services officer named Grissom recruited her to work at the lab. She started as an assistant technician and has worked her way up over a decade to become a CSI level Three.

Catherine was born on a ranch in western Montana. She was the eldest daughter of fourth-generation ranchers, but the rural life was never for her. Catherine could ride before she could walk, but horses were always for taking her away from work. She left home for the first time as a sixteen-year-old. She lived in Seattle for a year with her would-be rock-star boyfriend, eking out a living as a waitress. When he left her for an older woman, she went find home wasn't there anymore. Her parents had been forced to sell their ranch and moved to town. They made it clear that Catherine was on her own. The next stop for Catherine was Las Vegas. She waited tables until she discovered a much more lucrative line of work: exotic dancing. The men loved her and the money poured in. Catherine spent it all on school and the aspiring career of her music-producing boyfriend, Eddie. Dating turned to engagement which turned to marriage. When their turbulent quasi-romance ended, Eddie left her with ten dollars in the bank, a coke habit, and a small child, Lindsey. Catherine pulled it together for her own sake and for the sake of her daughter. She didn't become a CSI because she wanted to right the wrongs of the world - she became a CSI because it makes her feel like a kid solving puzzles. She loves the challenge and she loves the buzz of working a case. It's a high for her - and anything that makes Catherine feel as good as she does can't be all bad.