I'm looking for a science fiction book. There is a station orbiting earth and a message showing aliens being attacked by other aliens. A warning to humanity. I recall the evil aliens looking like a clown. There is cloning later in the book. People are interrogated and killed. Then the next clone is brought in.
I am reminded of Pohl's Eschaton Sequence
In this series of novels, aliens occupy a human space station in Earth orbit, and have teleportation technology allowing humans and others to be duplicated (thus the clones you remember). In addition, the aliens on the space station send warning messages to Earth about the dangers of a different faction of aliens. Some of the aliens look silly - humans call them "Dopeys," "Docs" or "Scarecrows," which may correspond to the "clown" memory you have.
This review of the third book in the series mentions the interrogation of duplicates:
At the start of the novel, Dannerman is cloned by a group of alien Horch and imprisoned so they can interrogate him about life on our planet.