How does Andrews use the "red herring" in the novel, The Newcomer?

The author presents several red herrings and mysteries that lead the reader to specific thoughts and ideas. For example, it seems clear that Evan killed Tanya but Letty finds a recording of Declan's arrival at Tanya's apartment in New York City before she was killed. That is one of several red herrings that make the reader wonder if someone else is to blame but the author then brings the murder back to Evan. There seem to be several situations that are overly convenient, such as the fact that Declan happened to know that Evan had a reward out for Maya's return. Most readers will be willing to overlook these as typical of the genre and acceptable for the situation.