From 2009 through 2014 Thiessen appeared in the crime series as.
In 1992, she starred in her first television movies and , making her film debut in in 1993.
She was the first actress to join directly the main cast of the show and portrayed Valerie until 1998, when she left in the early episodes of the ninth season of the show.
Basketball player also revealed publicly that he was a fan of Thiessen back then, when she sent him an autographed Saved by the Bell-era photograph of herself for his 29th birthday in 2014.
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In 2003, she launched her production company Tit 4 Tat Productions, producing and directing the short film Just Pray in 2005, which earned distinctions at several film festivals, including winning Best Score at the Rhode Island International Film Festival, an Academy Award qualifying festival.