It's the third time in three years that boards in Ohio and Louisiana decided not to take action against Larry James, dean of professional psychology at Wright State University in Dayton.
"It has been determined that we are unable to proceed to formal action in this matter," Ohio Psychology Board investigator Carolyn Knauss said in a one-page letter dated Jan. 26.
Harvard Law School's International Human Rights Clinic, which helped research the complaint against James, released the letter to the AP late Wednesday.
The board's executive director, Ronald Ross, said Thursday that he could not comment on any complaints that result in no further action by the board.
A Wright State spokesman said a comment was forthcoming from the Dayton university.
The complaint says James oversaw abuse at Guantanamo Bay in Cuba in 2003, 2007 and 2008 when he served with the base's Behavioral Science Consultation Team.
"Detainees were systematically abused while Dr. James served on and allegedly led the Guantanamo BSCT," said the complaint filed last summer. It said he both endorsed the abuse and did nothing to prevent it.
In one instance, the complaint said, James initially watched without intervening while an interrogator and three guards subjected a near-naked man to sexual humiliation by forcing him to wear women's underwear, and only intervened when he was concerned someone might get hurt, according to the complaint.
James said in his 2008 book, "Fixing Hell," that the Army sent him to clean up abuses in Guantanamo and later in the Abu Ghraib detention center in Iraq.
He told the Dayton Daily News in 2009 that he doesn't understand why the allegations continue to come up.
"No matter what third party, objective review board or person, they've all come to the same conclusion - there's no probable cause," James said. "There's no detainee, there's no guard, there's no psychologist who's come forward and said, 'With my own eyes, I've seen Dr. James do X, Y or Z.'"
James did not immediately return a message left Thursday, while university spokesman George Heddleston said Wright State was pleased with the decision.
A Harvard lawyer said the complaint deserved a formal hearing.
"Ohio residents presented the board with more than enough evidence to support the sanctioning of Larry James for violating his obligations as a psychologist by using his professional skills to harm others," said Deborah Popowski of Harvard Law School's Human Rights Program.
Last year, the State Board of Examiners of Psychologists in Louisiana, where James is also licensed, declined to act on a similar complaint against him.
In 2008, the Ohio board in "determined that no foundation exists to support the initiation of formal proceedings serving to deny Dr. James admission to the Board's licensure examination," according to a copy of the board's response provided by the Harvard clinic.
In June 2007, 350 members of the American Psychological Association signed an open letter to its then-President Sharon Brehm requesting an investigation of James and other members of the association who served at Guantanamo Bay.
The association didn't investigate, but in 2008 it voted to ban its members from taking part in interrogations at Guantanamo and other military detention sites where it believes international law is being violated.
In Texas, the State Board of Examiners of Psychologists has scheduled a hearing Tuesday to consider the case of Jim Mitchell, who former U.S. intelligence officers say was involved in waterboarding two suspected terror suspects in overseas prisons.
In New York, a court has been asked to force an investigation into whether Army psychologist John Leso developed abusive interrogation techniques for detainees at Guantanamo Bay and should be stripped of his license.