Who is the 4th person?

[greatlit2003]

No: HPFGUIDX 54405

Hi everyone. I have a few questions concerning the Death Eaters: 
During the Longbottom trial that Harry witnesses in Dumbledore's 
Pensieve, 4 people were on trial: Crouch Jr., Mr. and Mrs. Lestrange 
(an assumption, but I think it's valid) and another man. Why does no 
one mention this man? Sirius told Harry the names of many Death 
Eaters, and he mentioned that Crouch Jr. and the Lestranges were in 
Azkaban. Voldemort mentioned the three of them also, and called 
them "faithful". But why does no one mention the 4th man? He too 
must have been a faithful Death Eater if he went looking for 
Voldemort. I don't think this omission is accidental. 

Also, what happened to the other Death Eaters who were caught? 
Antonin Dolohov and Augustus Rookwood? (I'm willing to believe that 
Rosier is dead since Moody seems to have witnessed his death, but we 
cannot yet be sure if Wilkes or Rosier are alive or not).

"greatlit"