Anyone arrested for drunk driving in Massachusetts has a right to have his condition independently evaluated by a private physician.
According to M.G.L. c. 263, § 5A,
A person held in custody at a police station or other place of detention, charged with operating a motor vehicle while under the influence of intoxicating liquor, shall have the right, at his request and at his expense, to be examined immediately by a physician selected by him.
Police must inform you of this right at the start of the booking process.
Additionally, the officer booking you must provide you with a copy of the law or have the text of the law posted where it can be easily read.
Although police must give you a “reasonable opportunity” to arrange a medical evaluation, they have no duty to assist you. They simply cannot impede your efforts.
The SJC has held that
[U]nder G. L. c. 263, Section 5A, the police must not prevent or hinder an individual’s timely, reasonable attempts to obtain an independent examination, but they need not assist him. They need only inform him of his rights and allow him access to a telephone.
Commonwealth v. Alano, 388 Mass. 871, 879 (1983).
The same opinion states,
Thus, it has been held that the police cannot constitutionally refuse to allow the accused to call a physician, or other person who could arrange for a physical examination. But it has been held that the police need not take the defendant to a hospital. Nor need they locate a physician and take the accused to him, or arrange for a doctor to come to the jail. (Citations and quotations omitted.)
So what happens if the cops do, in fact, violate your 5A rights?
Again, quoting the SJC:
Where a defendant’s right under s. 5A has been violated, the violation itself is prima facie evidence that the defendant has been prejudiced in that his opportunity to obtain and present potentially exculpatory evidence has been restricted or destroyed.
Commonwealth v. King, 429 Mass. 169 (1999).
Nevertheless,
This presumption of prejudice…may be overcome by overwhelming evidence of intoxication…or by other evidence indicating that the omission was not prejudicial in the circumstances.
Id.