Polygraph Tests in Michigan CSC Cases (MCL 776.21)

Michigan has a polygraph statute written specifically for criminal sexual conduct (CSC) cases. Under MCL 776.21, a defendant alleged to have committed a CSC offense must be given a polygraph examination if he or she requests one, and a law enforcement officer may not request or order a victim to take one.^[1][2] The statute does not make the results admissible in court, and it does not say what a prosecutor must do with them.^[5][6]

This page goes through the statute subsection by subsection, then the court decisions that fill in what it leaves unsaid.

The statute at a glance

MCL 776.21 was added by a 1980 public act and took effect March 31, 1981.^[6] It has five subsections.

Subsection	What it says
(1)	Defines "law enforcement officer" and "victim."[3]
(2)	A law enforcement officer shall not request or order a victim to submit to a polygraph examination or lie detector test, and shall not inform a victim of the option unless the victim inquires or subsection (3) applies.[2]
(3)	A law enforcement officer shall inform the victim when the accused has voluntarily submitted to a test and the test indicates that the person may not have committed the crime.[4]
(4)	Subsections (2) and (3) apply only to a test requested, ordered or given in regard to a person being a victim.[4]
(5)	A defendant who allegedly has committed a covered offense shall be given a polygraph examination or lie detector test if the defendant requests it.[1]

The covered offenses are the same throughout: first-, second-, third- and fourth-degree criminal sexual conduct and assault with intent to commit criminal sexual conduct.^[1][3] Those offenses are described in the overview of the four degrees. The statute does not extend to other sex offenses.

The accused person's right to a polygraph

Subsection (5) is short: the defendant "shall be given a polygraph examination or lie detector test if the defendant requests it."^[1] Three points come from the courts.

How long the right lasts

The Michigan Supreme Court addressed timing in People v Phillips (2003). Because the statute sets no time limit, "the right is lost only when the presumption of innocence has been displaced by a finding of guilt, i.e., when an accused is no longer 'alleged' to have committed the offense."^[7] As the state's Sexual Assault Benchbook describes the case, the defendant asked for a polygraph during jury deliberations and the Court concluded the request was timely.^[8]

The same decision limits the remedy. Failure to grant a timely request does not require a new trial unless it is more probable than not that the error was outcome-determinative.^[8]

Counsel

A defendant has the right to have counsel present during a polygraph examination and during any questioning following the examination when the examination occurs after the Sixth Amendment right to counsel has attached.^[9] The benchbook notes that a defendant may waive that right and that the waiver may extend to post-examination questioning.^[10]

Recording

According to the benchbook, the statutory right to a polygraph examination does not include the right to have the examination tape-recorded.^[11] That statement rests on a Court of Appeals decision that was later overruled on other grounds.^[11]

What the statute leaves out

MCL 776.21 does not say who administers the test, who pays for it, or what follows from a result.^[6] Practice on those points varies by county and agency, and this guide states no rule about them.

Polygraphs and the person who reported

Subsection (2) protects the complainant in two ways. An officer may not request or order a victim to submit to a polygraph. And an officer may not inform a victim of the option of taking one "unless the victim inquires concerning such a test or as provided by subsection (3)."^[2]

"Law enforcement officer" is defined broadly. It means a police officer of a county, city, village, township or the state; a college or university public safety officer; a prosecuting attorney, assistant prosecuting attorney or an investigator for the prosecutor's office; or any other person whose duty is to enforce the laws of this state.^[3] "Victim" means a person who is a victim of one of the covered criminal sexual conduct offenses.^[3]

The statute regulates what officers may do. It is not written as a rule about what a victim may choose to ask.^[2] Other rights of people who report are collected in Rights of sexual assault survivors in Michigan.

What the victim must be told

Subsection (3) creates a notice duty that runs to the victim. A law enforcement officer "shall inform the victim when the person accused of a crime specified in subsection (1)(b) has voluntarily submitted to a polygraphic examination or lie detector test and the test indicates that the person may not have committed the crime."^[4]

The duty has conditions built into its wording: the test was voluntary, and its result indicates the accused may not have committed the crime.^[4] The statute does not require notice of other results.

Are polygraph results admissible?

Not at a criminal trial. In People v Kahley (2007), the Court of Appeals said: "[T]estimony concerning a defendant's polygraph examination is not admissible in a criminal prosecution," and "It is plain error for the jury to be presented with the results of a polygraph examination."^[5]

Error of that kind does not always undo a conviction. As the benchbook describes Kahley, reversal was not required there because the reference to the defendant's refusal to take a polygraph was brief and not repeated, the prosecutor did not argue guilt from it, the defendant himself testified that he had asked for a test, and the defendant had confessed.^[12]

So the statutory right and the evidence rule point in different directions. A defendant charged with a CSC offense has a right to the test, and neither side may put testimony about it before the jury.^[1][5] Whether results may be considered in other settings, such as a post-trial motion, is a subject the sources reviewed for this page do not cover.

What a result changes, legally

Question	What the sources say
Does a favorable result require dismissal?	The statute contains no such provision.[6]
Who decides whether to charge or continue?	The prosecuting attorney, whose signed authorization is required before a warrant or summons can issue for anything other than a minor offense.[13]
Does the victim learn of a favorable result?	Yes, where the accused voluntarily took the test and it indicates the person may not have committed the crime.[4]
Can the jury hear about it?	Testimony concerning a defendant's polygraph examination is not admissible in a criminal prosecution.[5]

How prosecutors weigh evidence that will never reach a jury is a matter of each office's practice, which varies. The legal standards for charging are covered in Who decides whether to charge.

Before any charge is filed

Subsection (5) speaks of a "defendant who allegedly has committed a crime."^[1] The Supreme Court's decision in Phillips addressed when the right ends, not when it begins.^[7] Whether the statute gives a person who is under investigation but not yet charged an enforceable right to a police-administered test is not answered by the sources reviewed for this guide.

A police polygraph before charges also involves the rules on police questioning. Miranda's safeguards are tied to custodial interrogation, and a party's own statements, offered against that party, are not hearsay.^[14][15] Those rules are explained in When a detective calls, and the role of counsel at this stage in Do you need a lawyer before charges are filed?

What people get wrong

• "The defendant can make the accuser take a lie detector test." The statute bars officers from even requesting one from a victim.^[2]
• "Passing gets the case dismissed." The statute gives a right to the test and a notice duty to the victim; it contains no dismissal provision.^[1][4][6]
• "Refusing a polygraph can be used against you at trial." Testimony concerning a defendant's polygraph examination is not admissible in a criminal prosecution, and Kahley treated a reference to a defendant's refusal as error, though not reversible error on that case's facts.^[5][12]
• "It is too late to ask once trial starts." The Supreme Court has said the right is lost only when the presumption of innocence has been displaced by a finding of guilt.^[7]
• "This applies to any sex offense." The statute lists the four CSC degrees and assault with intent to commit CSC.^[1]

Credibility is decided by the jury from the evidence admitted at trial.^[16] How that works when the case rests on two accounts is covered in cases without other witnesses and When the allegation is false: how courts test credibility. The sister guide discusses polygraphs outside the CSC statute in Polygraph tests in domestic violence cases.