Police Foundation document also details the carnage found at the scene of the shooting, which killed 14 people.
"Terrorists must not be permitted to provide for their designated beneficiaries through their crimes," says U.S. Attorney Eileen Decker.
The bureau may be allowed to withhold how it cracked an iPhone belonging to one of the San Bernardino shooters.
Syed Rizwan Farook may have contemplated an attack on a U.S. target as early as 2011.
Homegrown extremists such as the San Bernardino attackers give ISIS a terrifying new weapon.
Syed Farook and Tashfeen Malik were influenced by foreign militant organizations, FBI Director James Comey said.
Authorities say Syed Farook and Tashfeen Malik killed 14 people in California last week.
The vigil came a day after two shooters killed 14 people and injured 21 others.
Syed Farook and Tashfeen Malik were married and had a 6-month-old baby.