Please help on an eviction case

I have an section-8 tenant (disabled old man) who is taking care by his grandson. The grandson trashed the house and always late on all the payments (rent/pet fee/utility/yard maintenace/...) I filed the eviction and won. I asked constable to excuate the eviction. But the grandson did not show up in the house, and left the old man in the house. The sheriff did not want to move the disable old man out of the house.

(It is in Texas)

My questions:
1) Did I have the right (court order) to order the sheriff to move the old man out of the house?
2) I feel bad if moving him out and left alone on the street. What can I do in this case?
3) Is there any legal way to solve this problem?

Thank you very much for any suggestion.