We believe there could be other offenders and so we are currently concentrating on determining exactly what happened on Sunday night.
A scene watch remains in place and I want to thank local residents once again for their help and patience whilst investigations continue.
We have a dedicated team working to solve this crime and bring any offenders to justice and I want to reassure residents that this appears to be an isolated crime and not a random attack.”
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Thursday morning's weather for the east of the region
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Prisons will be expected to reform prisoners as well as punish them under new proposals, set to be unveiled on Thursday.