A lengthy report into the San Bernardino terror attack reveals new details about the killings last year and the way the husband and wife who carried them out died in a police shootout.

The report obtained Friday by The Associated Press provides an in-depth look at the chaos and confusion as the Islamic extremists opened fire at a meeting of the man's colleagues.

The draft report by the Police Foundation, a policy study group, and the Department of Justice says three men tried to stop the armed couple, rushing at them before being shot.

Syed Rizwan Farook and his wife, Tashfeen Malik, killed 14 in the massacre at a training event and holiday gathering of county food inspectors. They wounded 24 people before being killed later in a police shootout.