The US army psychiatrist convicted of the Fort Hood massacre that killed 13 people is due to begin the sentencing phase of his trial possibly facing the death penalty.

A soldier shot five times said he locked eyes with Fort Hood massacre suspect Nidal Hasan after the US Army psychiatrist cried “Allahu Akbar” and fired into a crowd of troops preparing for deployment.

A Pentagon inquiry into the case of the alleged Fort Hood shooter, blamed for killing 13 people, could lead to punishment of up to eight Army officers, a US official said.

US federal agencies are blaming each other over security lapses involving the Fort Hood massacre gunman Nidal Hasan.