Chapter 5 Prosecutors, Police, and Preservation of Evidence

• Jurisdiction: United States

Chapter 5 Prosecutors, Police, and Preservation of Evidence

A. Introduction

In this chapter we consider how the criminal justice system officials most closely identified with establishing offenders' guilt—prosecutors and the police—can contribute to wrongful convictions and, just as importantly, also can occupy critical roles in helping guard against the erroneous conviction of the innocent. Although there are exceptions, for example, innocent people who are ensnared in scandals involving fabricated evidence and the knowing use of perjury,¹ prosecutors and police officers in general have every reason to be solidly averse to wrongful convictions. No legitimate law enforcement interests are advanced by miscarriages of justice that result in innocent people being punished and the guilty remaining free.

Nevertheless, as we discussed in Chapter 2, prosecutors and the police are as susceptible as others to tunnel vision, institutional and organizational pressures, norms, and incentives, and other influences that help shape if not occasionally cloud or distort their judgment. The inherent ambiguities associated with criminal investigations and prosecutions, pressing caseloads, and the limited time and resources at their disposal make law enforcement officials' responsibilities all the more challenging. Thus, it is not surprising that prosecutorial and policing duties sometimes are inadvertently breached, while at other times official misconduct occurs recklessly or purposefully. Such transgressions can contribute to wrongful convictions.

As we noted in Chapter 1, the Innocence Project has identified government misconduct as contributing to 15.1% (54/358) of the wrongful convictions exposed through DNA analysis through August 1, 2018.² The Innocence Project generally describes government misconduct as "fraud, negligence or [other] misconduct by prosecutors or police."³ Its category of prosecutorial misconduct includes:

• Withholding exculpatory evidence from defense
• Deliberately mishandling, mistreating or destroying evidence
• Allowing witnesses they know or should know are not truthful to testify
• Pressuring defense witnesses not to testify

• Relying on fraudulent forensic experts
• Making misleading arguments that overstate the probative value of testimony.⁴

Police misconduct as defined by the Innocence Project includes:

• Employing suggestion when conducting identification procedures
• Coercing false confessions
• Lying or intentionally misleading jurors about their observations
• Failing to turn over exculpatory evidence to prosecutors
• Providing incentives to secure unreliable evidence from informants.⁵

Official misconduct is identified as contributing to a significantly higher proportion of the convictions for the exoneration cases included on the National Registry of Exonerations: 52.1% (1,173/2,253 through August 1, 2018).⁶ The NRE defines official misconduct as occurring when: "Police, prosecutors, or other government officials significantly abused their authority or the judicial process in a manner that contributed to the exoneree's conviction."⁷ Official misconduct is second only to perjury and false accusations (which factor in 57% of the identified wrongful convictions) in contributing to the erroneous convictions in the NRE database and it is especially prevalent in wrongful homicide (murder and manslaughter) convictions (70%).⁸

In this chapter we first consider the prosecutor's duties as advocate for the government and how those duties give rise to constitutional imperatives against knowingly presenting untruthful testimony or allowing perjury to go uncorrected. We then explore the affirmative prosecutorial obligation to disclose evidence that may help defendants establish their innocence. Evidence cannot be disclosed or used if it is not secured and retained. Thus, we next examine the police's obligations with respect to collecting and preserving evidence that may be probative of guilt or innocence. We conclude by considering policies governing the preservation of evidence and allowing defendants' access to evidence in the government's possession so it can be tested in connection with post-conviction claims of innocence.

B. The Prosecutor's Duties

1. Perjured Testimony

Miller v. Pate 386 U.S. 1, 87 S.Ct. 785, 17 L.Ed.2d 690 (1967)

Mr. Justice STEWART delivered the opinion of the Court.

On November 26, 1955, in Canton, Illinois, an eight-year-old girl died as the result of a brutal sexual attack. The petitioner was charged with her murder.

Prior to his trial in an Illinois court, his counsel filed a motion for an order permitting a scientific inspection of the physical evidence the prosecution intended to introduce. The motion was resisted by the prosecution and denied by the court. The jury trial ended in a verdict of guilty and a sentence of death. On appeal the judgment was affirmed by the Supreme Court of Illinois. On the basis of leads developed at a subsequent unsuccessful state clemency hearing, the petitioner applied to a federal district court for a writ of habeas corpus. After a hearing, the court granted the writ and ordered the petitioner's release or prompt retrial. The Court of Appeals reversed, and we granted certiorari to consider whether the trial that led to the petitioner's conviction was constitutionally valid. We have concluded that it was not.

There were no eyewitnesses to the brutal crime which the petitioner was charged with perpetrating. A vital component of the case against him was a pair of men's underwear shorts covered with large, dark, reddish-brown stains—People's Exhibit 3 in the trial record. These shorts had been found by a Canton policeman in a place known as the Van Buren Flats three days after the murder. The Van Buren Flats were about a mile from the scene of the crime. It was the prosecution's theory that the petitioner had been wearing these shorts when he committed the murder, and that he had afterwards removed and discarded them at the Van Buren Flats.

During the presentation of the prosecution's case, People's Exhibit 3 was variously described by witnesses in such terms as the "bloody shorts" and "a pair of jockey shorts stained with blood." Early in the trial the victim's mother testified that her daughter "had type 'A' positive blood." Evidence was later introduced to show that the petitioner's blood "was of group 'O'."

Against this background the jury heard the testimony of a chemist for the State Bureau of Crime Identification. The prosecution established his qualifications as an expert, whose "duties include blood identification, grouping and typing both dry and fresh stains," and who had "made approximately one thousand blood typing analyses while at the State Bureau." His crucial testimony was as follows:

"I examined and tested 'People's Exhibit 3' to determine the nature of the staining material upon it. The result of the first test was that this material upon the shorts is blood. I made a second examination which disclosed that the blood is of human origin. I made a further examination which disclosed that the blood is of group 'A'."

The petitioner, testifying in his own behalf, denied that he had ever owned or worn the shorts in evidence as People's Exhibit 3. He himself referred to the shorts as having "dried blood on them."

In argument to the jury the prosecutor made the most of People's Exhibit 3:

"Those shorts were found in the Van Buren Flats, with blood. What type blood? Not 'O' blood as the defendant has, but 'A'—type 'A'.''

And later in his argument he said to the jury:

"And, if you will recall, it has never been contradicted the blood type of Janice May was blood type 'A' positive. Blood type 'A'. Blood type 'A' on these shorts. It wasn't 'O' type as the defendant has. It is 'A' type, what the little girl had.'"

Such was the state of the evidence with respect to People's Exhibit 3 as the case went to the jury. And such was the state of the record as the judgment of conviction was reviewed by the Supreme Court of Illinois. The "blood stained shorts" clearly played a vital part in the case for the prosecution. They were an important link in the chain of circumstantial evidence against the petitioner, and, in the context of the revolting crime with which he was charged, their gruesomely emotional impact upon the jury was incalculable.

So matters stood with respect to People's Exhibit 3, until the present habeas corpus pro-ceeding in the Federal District Court. In this proceeding the State was ordered to produce the stained shorts, and they were admitted in evidence. It was established that their appearance was the same as when they had been introduced at the trial as People's Exhibit 3. The petitioner was permitted to have the shorts examined by a chemical microanalyst. What the microanalyst found cast an extraordinary new light on People's Exhibit 3. The reddish-brown stains on the shorts were not blood, but paint.

... He found "no traces of human blood." The State did not dispute this testimony, its counsel contenting himself with prevailing upon the witness to concede on cross-examination that he could not swear that there had never been any blood on the shorts.

It was further established that counsel for the prosecution had known at the time of the trial that the shorts were stained with paint. The prosecutor even admitted that the Canton police had prepared a memorandum attempting to explain "how this exhibit contains all the paint on it." ...

The record of the petitioner's trial reflects the prosecution's consistent and repeated misrepresentation that People's Exhibit 3 was, indeed, "a garment heavily stained with blood." The prosecution's whole theory with respect to the exhibit depended upon that misrepresentation. For the theory was that the victim's assailant had discarded the shorts because they were stained with blood. A pair of paint-stained shorts, found in an abandoned building a mile away from the scene of the crime, was...