Reinhard Halfman (1871-1955) might have lived in Canada (most likely Saskatchewan). He supposedly died in Canada probably living with his sister, Mary Honnef. I could not find him in the 1920 or 1930 US censuses. Maybe he was in Canada during that period.
Here's a summary of where he lived:
1910 - Elgin, NE (living with his sister Catherine Josten)
1940 - Elgin, NE (living with his sister Catherine Josten)
1949 - Elgin, NE (according to the obit of his sister Anna Remackel)
1955 - Supposedly died in Canada and buried in Elgin, NE
Yes, Reinhard's brother, Joseph, was murdered in Windthorst. Any additional info on Joseph would be appreciated.