Definitely Linked To Al Qaeda:
Sinh Vinh Ngo Nguyen Arrested Before Joining Al Qaida October 17, 2013 24-year-old Sinh Vinh Ngo Nguyen of Garden Grove in Southern California was arrested and charged with attempting to join al-Qaida. He was charged with lying on a U.S. passport application to aid international terrorism was planning to travel to Pakistan. He was found with a fake passport and had recently traveled to Lebanon and Syria to help the Free Syrian Army.
Vietnamese Computer Expert Arrested For Helping Al Qaeda June 29, 2012: Minh Quang Pham, 29 Pham was wanted in the US for terrorism related offences and was arrested in the UK. Pham swore an oath of allegiance to al-Qaeda in the Arabian Peninsula (AQAP) after leaving Britain to join the terrorist group in December 2010. He received military-style training and met with the American citizens Anwar al-Awlaki and Samir Khan who were producing online propaganda for AQAP including the notorious on-line magazine called “Inspire” before returning to Britain eight months later. Pham is of Vietnamese heritage but had been living in New Cross, South London since at least 2005 where he ran his own computer company. Vietnam has 63,146 Muslims according to the 1999 census, less than one per cent of the population, mostly from Cham ethnic group, who are related to Malays
Taliban took credit:
The perpetrator was 41-year-old Jiverly Antares Wong (December 8, 1967 – April 3, 2009), a resident ofJohnson City, New York. Wong was born into an ethnic Chinese (Hoa) family in South Vietnam. The US discounted claims by the Taliban that accepted responsibility for the shootings
Possible, but no official motive:
February 11, 2013 Nhan Lap Tran Shoots At Random Cars in Oakdale MN Near St Paul Vietnamese immigrant Nhan Lap Tran fires at and hits passing cars. He killed 9 year old fourth grader Devin Aryal, who was in his car seat in his mother's minivan. His stated motive was "noisy cars made him shoot randomly". Not random if he was able to shoot out tires, windows and hit a child in a car seat whizzing by at 30 mph with a handgun