Randall's Son

Randall's Son is an unnamed and unseen character in Friday the 13th: Back from the Grave.

Pre-Pinehurst
Before Pinehurst, he was born to Cathy Blackburne and Randall Blackburne and had a Sister. Randall very much loved his son, and cared for him very much. Unfortunately, one day, Randall's Son was killed in a car crash involving his father, Marco McBride and Garth McBride, which also killed the latter.

Death
Killed by During a drive, Marco got drunk and got in a car crash, killing both Randall's son and Marco's brother, Garth.
 * Marco McBride (Accidentally)

Randall Blackburne
As he was the son of Randall and the main reason for Randall's madness, it is obvious that Randall loved and cared for his son very much, and was devastated over his death.

Cathy Blackburne
Due to him being the son of Cathy, it is very likely that Cathy loved him and was devastated over his death.

Marco McBride
Despite never interacting, it is shown that Marco feels tremendous guilt over causing the death of both Randall's son and Garth.

Trivia

 * Randall's son is the youngest deceased character in the series.