1.Police simply said "teams were yesterday attempting to recover CCTV in the area to establish whether the sighting was credible or not."
2.“None of those [past] sightings have so far proved to be positive and we are actually today [Weds] doing some work on a sighting last night."
Conclusion：because the police are still clueless about Du's whereabout, thus, they believed that "somebody in the community is looking after him".
