After the cats in the cage were sent to the vet, and the caregiver and I had walked and spoken with everyone at home in the block, I went down to do some mediations. These few blocks always seem to have problems.
This complaint was about the leftover food in the staircase landing - I went there and lo and behold, there was food. I spoke to the person who is supposed to be feeding. He denied it but said he did know the cat, and that he didn't mind cleaning up the food whenever he saw it.