Gov. Nathan Deal, a former juvenile court judge, appointed Howell in January 2011 soon after he was inaugurated. An official announcement is expected Monday.
The spokesperson for the DJJ declined to comment.
According to the letter, at the request of Deal, Howell will become General Counsel for the Department of Behavioral Health & Developmental Disabilities (DBHDD) to "ensure one of our major agencies is running smoothly through a federal settlement and transition in service delivery." In 2010, state and federal officials reached an agreement that places DBHDD's focus on community-based care following a three-year investigation by the U.S. Justice Department into allegations DBHDD was violating patients' civil rights.
A spokesperson for the Department of Behavioral Health denied any knowledge of Howell's move saying only that Dr. Frank E. Shelp will remain commissioner.
In the letter, Howell reflected on her short tenure as DJJ commissioner.
"I have counted every day that I was Commissioner," she wrote, "to ensure that I took full advantage of the opportunity to serve and improve our agency."
Writing to her staff she continued:
I have tremendous respect and awe for DJJ staff's unwavering commitment to helping youth and keeping our community safe. On the difficult days, recall the positive impact you have had - when former youth call to say they've found and kept jobs, have finished school, gotten married, or started their own family and are happy. These are the stories of your success.
Concluding the letter she wrote, "Remember, offer hope and youth change."
Howell, a former assistant public defender in the DeKalb County, Ga. Juvenile Court, first joined the DJJ in 2005 as legal services director. A year later she was named deputy commissioner. According to her biography on the DJJ website, Howell managed many different divisions within the DJJ including legal services, apprehensions and medical and behavioral health.
In recent days, Howell came under fire from a local Atlanta television station when it was discovered she had been receiving a monthly car allowance of more than $580, along with access to a state-owned car. The television station, WSB-TV, reported the state stopped approving car allowances in 2005. WSB-TV also reported a mileage log for the vehicle failed to account for more than 2,000 miles. The log showed only Howell and two close associates used the car, which the state leases for nearly $500 per month.
Howell reimbursed the state for $4,100, the amount of the car allowance she received minus taxes paid. WSB-TV reported the two previous DJJ commissioners also received car allowances but could not determine who approved the funds.