From Longman Dictionary of Contemporary Englishprowlerprowl‧er /ˈpraʊlə $ -ər/ noun [countable] SCCa person who follows someone or hides near their house, especially at night, in order to frighten or harm them or to steal something The police were called after a prowler was spotted near their home.
Examples from the Corpus
prowler• Prowler fears: Police were called after a prowler was spotted near the army married quarters in Ripon.• Capitol police bolted and locked all the windows, in case a prowler was coming in after everyone had left: no luck.• Across the rooftops, a lone cop prowler was the only thing moving on the cold expanse of the Grand Canal.• It could be Fenella returning home - or it could be a nocturnal prowler.• It was reported that she disturbed the prowler when she arrived back unexpectedly at her family's Melbourne home.• Chapel can't remember the exact sequence of events, but he reckons that the prowler might well have been Saunders.• The boy managed to struggle free and ran off unharmed ... the prowler escaped.• It was not a place that unexpected prowlers would ever escape from. 