A former brig counselor, Blenis said the letter was a "red flag" for potential self-injury. He said he considered it along with Manning's acknowledged history of suicidal thoughts shortly after his arrest, and his odd behavior at Quantico such as dancing alone in his cell and licking the cell bars during what the defense has characterized as a sleepwalking episode.
Asked by Coombs why Manning's gender-identification issues increased his risk of self-injury, Blenis replied, "That's not normal, sir."
"When you add that on top of a few other things we've talked about, it just shows he's not stable," Blenis said. "It's a cause for concern."
Manning was arrested in May 2010, before the military lifted a ban on homosexuals serving openly in the armed services.
Manning's lawyers must show that his treatment at Quantico was either intentional punishment or so egregious that it was tantamount to punishment. The government has the burden of proving by preponderance of the evidence that it had a legitimate purpose in imposing the restrictions.
The judge, Col. Denise Lind, could dismiss all charges if she finds for the defense but military legal experts say that's unlikely. A more common remedy is extra credit at sentencing for time served. Manning's lawyers have asked for 10-for-1 credit if the judge refuses to dismiss the case.
Manning's treatment drew international attention and was condemned by his supporters, who consider him a heroic whistleblower. United Nations torture investigator Juan E. Mendez called Manning's treatment "cruel, inhuman and degrading."
The 24-year-old native of Crescent, Okla., is charged with 22 offenses, including aiding the enemy, which carries a maximum penalty of life in prison. He's accused of leaking hundreds of thousands of classified Iraq and Afghanistan war logs and more than 250,000 diplomatic cables while working as an intelligence analyst in Baghdad in 2009 and 2010. He's also charged with leaking a 2007 video clip of a U.S. helicopter crew gunning down 11 men later found to have included a Reuters news photographer and his driver. The Pentagon concluded the troops acted appropriately, having mistaken the camera equipment for weapons.