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4 min read

Examining Prosecutorial Immunity: The Case of Larry Trent Roberts

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Larry Trent Roberts was exonerated after spending 13 years in prison for a murder he did not commit. He sued the assistant district attorney John Baer and others under § 1983 for fabricating evidence used to wrongly convict him. Baer attempted to dismiss the case on the grounds of absolute prosecutorial immunity, but the district court denied his motion. Baer appealed, arguing that his search for a new witness had served a prosecutorial function.

The case examined the question of whether an assistant district attorney is eligible for absolute prosecutorial immunity in a § 1983 action, particularly the significance of both the timing of the prosecutor's actions and the specific role being fulfilled. Furthermore, it explored the burden of proof required for a prosecutor to assert an absolute immunity defense in a motion to dismiss.


In 2005, Duwan Stern was murdered in Harrisburg, PA. Two witnesses saw Thomas Mullen and another man lean into Stern's car after the shooting. Detective David Lau focused on Jermaine Roberts as a suspect due to their controversial history. Lau manipulated a witness into identifying Roberts and encouraged Mullen to falsely testify that Roberts confessed. Lau and prosecutor Nicholas Baer then fabricated evidence to establish a motive, approaching a known jailhouse snitch to provide false testimony that Roberts and Stern had a dispute over drug debts. Baer told the jury the snitch's testimony would establish motive, even though he knew the snitch was not credible. 

Despite no evidence against Roberts, Lau arrested him for Stern's murder. Roberts was wrongfully convicted based on the fabricated evidence.

The District Court Denies Baer's Motion to Dismiss

In 2018, a court in Pennsylvania ruled that Roberts should get a new trial. He was tried again, and this time the jury found him not guilty of all the charges against him. Subsequently, Roberts filed a complaint in the District Court, claiming he had been wrongfully convicted and naming Lau, Bear and the City of Harrisburg in his complaint.

Of significance were two claims in the complaint that accused Baer of making up evidence and collaborating to fabricate evidence, which violated Roberts' constitutional rights under the Fourth and Fourteenth Amendments. One claim alleged that Baer coerced a jailhouse informant to give a false statement to incriminate Roberts. The other claim accused Baer and Lau of working together to create false evidence and wrongfully convict an innocent person.

In September 2021, Baer tried to have these claims dismissed by asserting that he was immune from prosecution for his role as a prosecutor in obtaining fabricated testimony. However, the District Court rejected this argument, stating that his actions were investigative rather than protected prosecutorial activities. Baer then decided to appeal this ruling.

 The Issue on Appeal: Prosecutorial Immunity

The sole issue on appeal is whether Baer functioned as an advocate or an investigator when he allegedly searched for a new witness to fabricate a motive for Roberts to kill Stern. If Baer's conduct served a prosecutorial function, he has absolute immunity. But if it went beyond advocacy into investigation, he does not have absolute immunity because that only applies to actions associated with litigation.

Prosecutors like Baer have absolute immunity for conduct serving a quasi-judicial function, meaning intimately associated with the judicial process. Immunity does not apply to administrative or investigative actions unrelated to litigation. The analysis has two steps - identify the conduct alleged, and determine what function it served. At the motion to dismiss stage, the prosecutor must show the conduct triggering immunity clearly appears on the face of the complaint.

The complaint alleges that after an associate refused to cooperate in providing false evidence of motive, Baer joined the investigation and sought out a jailhouse informant who would testify to motive. One month before trial, Baer found informant Potter, who he knew lacked credibility. Baer approached Potter, offered him a deal, and coerced him to provide false testimony on motive.

Baer argues his conduct served a prosecutorial function because it occurred right before trial to get Potter to testify. He relies on Yarris, where prosecutors had immunity for using incentives to elicit false testimony from an informant.

Roberts argues Baer's conduct was investigative because he sought out and coerced a jailhouse informant to make a statement to formulate motive evidence. He relies on Fogle, where prosecutors lacked immunity for soliciting false statements from informants.


Roberts has the stronger position. Baer's alleged search for a witness to generate evidence looks more like an investigator's work, not an advocate's trial preparation. Under the functional test, Fogle provides a closer match than Yarris. So the complaint alleges investigative conduct, meaning Baer is not entitled to absolute immunity at this stage.

Prosecutorial Immunity Requires a Fact-Specific Analysis

The court explains that determining whether a prosecutor is entitled to absolute immunity requires a fact-intensive inquiry focused on the specific conduct at issue. The timing of the conduct and its connection to a judicial proceeding are relevant considerations, but alone are not enough to establish absolute immunity. Immunity depends on whether the prosecutor was functioning as an advocate when engaging in the conduct. Bright-line rules based solely on the timing or connection to a case cannot resolve the immunity analysis.

Prosecutor's Search for New Witness Was Investigative

The court compares the prosecutor's alleged search for a new witness to provide false testimony to similar conduct alleged in a prior Third Circuit case, Fogle v. Sokol. As in Fogle, the prosecutor here allegedly sought a new witness to shore up a weakened case by providing fabricated testimony. The detailed allegations resemble Fogle, where the court held this conduct was investigative. The court concludes finding a new witness to coerce false testimony served an investigative function, so absolute immunity does not apply on the face of the complaint.

Prosecutor's Immunity Defense Can Be Revisited Later

While the prosecutor is not entitled to absolute immunity at this stage, the court explains he can reassert this defense later as the factual record develops. For now, the complaint's allegations control the analysis. But if the prosecutor shows through discovery that his conduct actually served a prosecutorial function, he may still establish absolute immunity. The denial of dismissal preserves his ability to make this showing based on a fuller record.

Complaint Allegations Control Immunity Analysis

In concluding the prosecutor is not immune, the court emphasizes that the complaint's factual allegations dictate the result at this stage. The court must accept these allegations as true when considering a motion to dismiss. Here, the alleged facts indicate the prosecutor's conduct was investigative. This does not preclude him from later proving his actions were prosecutorial, but for now the complaint controls.

Final Ruling and Dissenting Opinion

The dissent and majority disagreed if the ADA acted as an advocate or investigator. The majority followed Fogle that generating evidence is investigative. The dissent argued absolute immunity applies based on earlier cases and distinguished Fogle.

Majority Opinion

The majority affirmed. Prosecutors have absolute immunity for advocacy tasks associated with the judicial process, like preparing for trial. But they only get qualified immunity for investigative functions like searching for evidence pre-probable cause. The ADA's meeting with a witness occurred post-charges. But its purpose was generating evidence, an investigative function under Fogle. So the ADA gets only qualified immunity.

Dissenting Opinion

The dissent would grant absolute immunity. Prior cases held soliciting testimony to prepare for judicial proceedings is advocacy entitled to absolute immunity. Fogle conflicts with those holdings. The ADA met the witness to prepare trial testimony, so under the earlier cases he should have absolute immunity. His actions were also more like those in Yarris than the extensive investigative acts in Fogle. The conduct alleged is serious but absolute immunity applies.