I too am loving the names. And it certainly seems a lot easier!
page 103. Can anyone help with というのか! at the end of the middle sentence. The rest of the sentence reads I think The person in question swam across this river.
There are so many uses of という which can all seem quite confusing. My basic understanding here is that というの has turned the phrase into a noun (similar to how の can do this on its own) and this is followed by か making it a question.
So the whole sentence means something like, Did the criminal swim across this river?
To add to this, I get the feel of Spitz’s narration going “So you’re saying the suspect swam across the river?” Rather than Spitz simply concluding on his own what must have happened, I (as a mere learner lacking enough reading experience) get the impression Spitz is saying that by stopping at the river’s edge, his dog is telling him that this is as far as the criminal’s trail can be followed, and thus the criminal must have waded into the river.
A specifier (modifier) always comes before the word it’s modifying in Japanese, so we can infer that the main noun here is ブラック, and that it’s being modified (specified) by ラブラドール・レトリバー.