I think the groundskeeper lets him live there.
5 seconds sound clip from the Dirty Harry 1 movie soundboard.
You can hear this line at 01:04:02 in the Blu-ray version of the movie.
Quote context
[...]
- Excuse me doctor, could you give him something for his chest? He's in terrible pain!
- For Christ's sake, she'll be dead in an hour.
- I've got who he is! When they had football, he used to sell programs at the stadium.
- I think the groundskeeper lets him live there.
- There.
- Too much linguine. I'll find another way.
[...]