Actor Ashton Kutcher has stepped down as board chair of an anti-child trafficking group that he co-founded in the wake of criticism he received over a letter of support he penned on behalf of his former "That '70s Show" co-star Danny Masterson following Masterson's criminal conviction for raping two women.

In a resignation letter posted on the website of the group Thorn, Kutcher wrote that he "cannot allow my error in judgment to distract from our efforts and the children we serve."

In June, the 43-year-old Masterson was found guilty of raping two women at his Hollywood Hills home in the early 2000s.

Both Kutcher and his wife Mila Kunis, who also starred on the popular sitcom, were among dozens of colleagues, relatives and friends who wrote letters of support to a Los Angeles County judge ahead of Masterson's sentencing hearing last week asking for leniency.

Despite the letters, Masterson was sentenced to 30 years to life in prison, the maximum allowable under the law.

In his letter to L.A. County Superior Court Judge Charlaine F. Olmedo, Kutcher called Masterson a "role model" and "an extraordinarily honest and intentional human being" who "set an extraordinary standard around how you treat other people."

Kutcher also wrote that he believes Masterson is not an ongoing harm to society and that the accused actor is one of the few people he would trust to be alone with his children.

Following significant backlash, Kutcher and Kunis posted a video to social media in which they said they did not mean to discount the trauma and experiences of Masterson's victims.

"The letters were not written to question the legitimacy of the judicial system or the validity of the jury's ruling," Kunis said. "We support victims."

In his resignation letter Thursday, Kutcher wrote that he came to the decision to resign after he and Kunis "spent several days of listening, personal reflection, learning, and conversations with survivors and the employees and leadership at Thorn."

He went on to give a "heartfelt apology to all victims of sexual violence and everyone at Thorn who I hurt by what I did."

Kutcher, Kunis and Masterson co-starred on "That '70s Show" from 1998 to 2006. Masterson later starred with Kutcher in the Netflix comedy series "The Ranch," which ran for four seasons from 2016 to 2020. However, Masterson only appeared in the first three seasons and was fired from the show in December 2017 after the rape allegations surfaced.  

In:
• Danny Masterson
• Ashton Kutcher