Sergeant Ikaika Erik Kang was arrested following a year-long secret FBI probe involving undercover agents who posed as ISIS operatives and sympathisers.
The officer said he believed the man was trying to hijack a truck, but evidence from body cameras and witnesses suggests no such potential crime.
Muslim students visiting an Oklahoma lawmaker’s office in the state capitol were required to fill out a form that asked if they beat their wives and other questions that offended them, an Islamic advocacy group said.
A private ceremony was organised for family members of victims and survivors of the attack, according to San Bernardino County spokesman David Wert.
The trio included Syed Raheel Farook, whose brother Syed Rizwan Farook and sister-in-law, Pakistan-born Tashfeen Malik, killed 14 people in a rampage authorities have said was inspired by Islamist militants.