there were two

[azz]

a, He knew that the police had interrogated six of his victims. But there were two victims he didn't know they had interrogated.
b. He knew that the police had interrogated six of his victims. But there were two other victims he didn't know they had interrogated.
c. He knew that the police had interrogated six of his victims. But he didn't know they had interrogated two other victims.

d, He knew that the police had interrogated six of his victims. But he didn't know they had interrogated two victims as well.

Are the above grammatical and meaningful?

It seems to me that (d) doesn't make sense.

Many thanks

 

[jutfrank]

No, d. isn't right.

He knew that the police had interrogated six of his victims, but there were two others who he didn't know had also been interrogated.

 

[Ostap]

two other victims

As an option: two more victims.