surveillance

valvonta close Close observation of an individual or group; person or persons under suspicion.
continuous Continuous monitoring of disease occurrence for example.
puhekieltä systematic Systematic observation of places and people by visual, aural, electronic, photographic or other means.
{{quote-magazine|date=2012-12-14
puhekieltä In criminal law, an investigation process by which police gather evidence about crimes, or suspected crime, through continued observation of persons or places.
stakeout
(l)