The police open an investigation and determine that Anya's fingerprints on the bottle and glass were indeed planted. Lisa is placed under arrest based on a statement from Mrs. Roper, who had seen her handle the items shortly after Anya's death and had also seen her and Karl embrace.
This passage describes a scenario where the police suspect Lisa of being involved in a crime related to Anya's death. The evidence against her is circumstantial, relying on witness testimony and fingerprints that were planted.