“Fiancée” usually means the booty de jour, nothing more.
In this case Mr. Foster and his fiancee had been together since high school. Although getting involved with the leftist protests and participating in and getting swept up into the Antifa mentality cost him his life, it really is a sad story. How much more he could have contributed to society, and the well being of his fiancee if they had focused their attention elsewhere into something more positive.
Mr. Foster and his fiancee a few years ago. Source: The Daily Mail