If it were me in the situation you describe I would be very suspicious of this "sweetheart" deal. The chiropractor sends the lawyer referrals in return for a finder's fee and, no doubt, the lawyer reciprocates by sending his clients to the chiropractor for a diagnosis favorable to the lawyer's case.
At the least it is unethical and in some jurisdictions it may be outright illegal.
Law school scholarships are pretty much always merit-based.
The government programs giving grants to need-based candidates apply only to undergraduates. Thus, law schools usually get their scholarship funds from private donors or from a slice of the budget allotted after the school has collected exorbitant tuition fees from students. This means the law schools can do pretty much anything they want with the scholarship funds.
Pragmatics requires law schools to use available scholarship funds to attract students that will boost the schools reputation, rank, and classroom experience thus perpetuating the schools legacy as these well qualified students go into the workforce, hopefully make some money, and hopefully donate to their alma mater. Students with high LSAT/GPA scores (relative to the school's student body) will most often get scholarship offers.I suppose that schools might also use scholarship money to attract minority groups, but I don't have personal knowledge of that.
So what should you do? Get a good LSAT/GPA. Apply to schools where your LSAT/GPA is above the 75th percentile for the student body. These schools should be top tier or perhaps the only school in your legal market of choice. If you can't find a school where you match that description, you might want to have some second and third thoughts about the law school idea.
Assuming you find reputable schools where you qualify with scholarships, you will want to be careful about which scholarship you accept. Scholarship funds are not endless and schools will want to get bang for their buck. Consequently, you will see schemes offering you full tuition for all 3 years, but only if you're in the top whatever of the class. If they set the bar too high for you, you'll find yourself stuck at the school and paying a hefty tuition price after losing your scholarship. Other schools will waive out-of-state tuition prices, others will guarantee you a job to earn money, etc.
As for potential need-based opportunities, I'm sure that here and there one might find a generous benefactor who has set up some sort fund for need-based candidates . . . . but I wouldn't bother crossing my fingers on that one.