Police are warning residents in the Long Buckby area to be vigilant, following three recent burglaries.
Each of the offences took place when doors and windows had been left open, and could possibly had been prevented if the houses had been secured.
The burglaries took place overnight between Wednesday 26 and Thursday 27 June, in Pytchley Drive, Grasscroft and Harbridges Lane.
Items stolen were similar in all three offences: handbags, financial documents, electrical items and cash. In Harbridges Lane, the keys to a vehicle (which was subsequently stolen) were also taken.
Sergeant Graham Newitt of Daventry local response team said:“In each of these burglaries, opportunists have simply walked in and helped themselves.
“People must take care to keep their doors locked at night, and to close windows in rooms that are not in use. A window left ajar can be levered open further wide enough to let in an offender.
“Opportunist criminals will try a door and if it is open, they will simply walk in and take what they can.”
For further crime prevention advice and information about how to carry out a security survey on your home, visit Northamptonshire Police or call 101 and ask to speak to your local crime prevention officer.
Witnesses to this incident, or anyone with information, should call Northamptonshire Police on 101 - alternatively, information can be given anonymously to Crimestoppers on 0800 555 111.