Suspect or Suspicious

As adjectives, suspect and suspicious blend into near-synonyms, though suspicious has taken standard preference in most situations: suspicious circumstances, suspicious packages, and suspicious vans are far more common than suspect circumstances, suspect packages, and suspect vans, as are phrases like to be suspicious of. The main use for the adjectival suspect is when the noun is thought to be connected to a crime: Police have found the suspect van indicates that the van found is believed to be associated with a crime committed, not simply that the van is of questionable reputation.