Motive Unclear?

U.S.: Stabbing Attack At Mall In Minnesota Injures 8

https://www.stratfor.com/situation-report/us-stabbing-attack-mall-minnesota-injures-8?id=899b2d6282&uuid=ec4243ae-7ea7-4d4e-83ea-cb7bf3c62d89

Excerpt: The motive is unclear. The suspected attacker was said to have been wearing the uniform of a private security firm when the attack occurred and reportedly made references to Allah before he was killed. The attacker asked at least one person if they were Muslim.

ISIS-linked Amaq news agency claims attacker who stabbed eight at St. Cloud, Minnesota, mall was 'soldier of the Islamic State.' 
http://www.foxnews.com/us/2016/09/18/minnesota-mall-attacker-referenced-allah-before-stabbing-rampage-police-chief-says.html