Server :: Cron Job That Does The Backups?

I have a crontab related question which I am hoping someone can answer. I recently took over a Redhat Enterprise 5 Server, and I was told by the previous Server Admin that there is a cron job that does the backups. I ran the following command to get a list of all users:

Code:
cat /etc/passwd | grep "/home" |cut -d: -f1

I then ran the following command for each of those users to see if they have any crontabs associated with them:

Code:
crontab -u USER -l

It doesn't show any crontab entries for any users (including root). But I am positive that there is a scheduled job somewhere because the backups are still running every night.