There are a number of inheritors to a fortune who are getting killed by a mysterious somebody whom we do not see. Each death is novel, but not terribly graphic. Who did it?
1970
1987
1975
2003
2000
1976
1934
1931
1932
2018
1991
2006
1985
2009
2016
1967
1954
1959
2004
1955