With all due respect, the basis for DR law is not common law as in the US, but a form of Napoleonic Law.
As I understand the concept of "presumptive innocence" is not as prevalent here as the states because of the Napoleonic Code. So it may be entirely legally feasible to detain two women walking alone at night in an area known for prostitution and detain them within the construct of the constitution. An excellent example of my point would be the practice of "pretrial detention" with few avenues of appeal, which is pretty much being sentenced before you plea your case in court and almost would never happen in the states as "excessive bail" except in some of the most horrific crimes or repeat offenders under the Eighth Amendment of the US Constitution.
It's a different world here.
Const. Art 69. Section 3, guarantees each person "The right to be presumed innocent and to be treated as such, while their culpability has not been declared by means of irrevocable sentence;"
Prostitution is not illegal, so detaining them for something that is not a crime is prohibited.
A civil code country (like the DR) still has to follow their laws and constitution. However, I do understand it is a different world - A nation of Men, not of laws.
Pretrial detention (rightly or wrongly) is not considered punishment for criminal conduct, but rather (at least legally), a form of protection. For this reason you have things like Casa de Conductor (where you go if you have money instead of jail), demonstrating that pre-trial detention is not technically a form of punishment.