State Requests Audio From Key Witness In Millar Murder Trial

By DAMIEN FISHER, InDepthNH

The New Hampshire Attorney General’s Office isn’t saying exactly why it requested the audio from the lead witness's testimony in the Matthew Millar murder trial.

Former Department of Corrections Corporal Lesley Ann Cosgro was the only witness who told State Police investigators she saw Millar push his knee into Jason Rothe’s back during the botched room extraction that resulted in the Secure Psychiatric Unit patient’s death in the state Prison for Men.

Cosgro’s credibility was damaged during her testimony last month, and Millar ended up being acquitted by the Merrimack Superior Court jury.

Cosgro testified on June 20, and on June 26 New Hampshire Attorney General’s Office Criminal Justice Bureau Paralegal Autumn Sayball sent a letter to the court requesting the full audio.

“This office is requesting a copy of the June 20, 2025 audio testimony of Leslie-Ann (sic) Cosgro in regards to the above-captioned matter, with Judge St. Hilaire presiding,” Sayball wrote.

So far, Cosgro is seemingly the only witness for whom the Criminal Justice Bureau is seeking trial audio. Michael Garrity, spokesman for the New Hampshire Attorney General’s Office, downplayed any significance in the Bureau’s request.

“That request was made during the trial as a part of our routine trial work,” Garrity said.

Millar was prosecuted by the Public Integrity Unit of the Attorney General’s Office, not the Criminal Justice Bureau.

Cosgro did not respond to an email seeking comment. The DOC reports Cosgro is still a full-time counselor earning $34.14 per hour.

Rothe, 50, died on April 29, 2023 after fighting with several corrections officers who were attempting to remove him from a day room. Cosgro was the officer in charge that day and ordered the room extraction that went wrong. Millar, who was not part of the original extraction team, reportedly came to help after hearing radio reports the team was in danger from Rothe’s attacks.

The jury took less than two hours to acquit Millar at the end of his trial in Merrimack Superior Court in Concord earlier this month. During her testimony, Cosgro recanted her prior statement about Millar’s knee.

After telling State Police in 2023 that she saw Millar put his full weight onto Rothe’s back for up to several minutes, under oath and on the witness stand Cosgro was less clear, saying Millar’s knee was present for “seconds, flashes of seconds.”

The time difference was a huge blow to the state’s case. Both the expert use of force testimony and the medical evidence effectively relied on Cosgro's original statement that Millar’s knee was on Rothe’s for an extended period of time.

Cosgro initially made two statements to her DOC superiors after Rothe’s death, and in neither statement did she mention Millar’s knee or make any other accusation about excessive force. During her cross examination, Cosgro tried to deflect when defense attorney Jordan Strand pressed her on why, weeks later, she told State Police Millar had his knee on Rothe’s back for several minutes.

“I’m not going to jail for killing this guy,” Cosgro told state police investigators, according to the transcript of her statement.

Cosgro violated several DOC policies when she led the extraction team the day Rothe died. The team she assembled did not have enough staff, Cosgro did not have staff members put on protective gear, and she did not assign extraction duties to the members of the team, among other failures. During the violent confrontation with Rothe, Cosgro used her taser several times despite DOC policy limiting its use to three during extractions.

Before she met with State Police investigators in 2023, Cosgro was rattled by the ongoing criminal investigation as well as the fact she got a subpoena to appear before a grand jury, according to statements made in court. During Millar’s trial, Strand said Cosgro was scared of getting blamed for Rothe’s death for her own documented failures in the incident.

“You thought they were going to pin the death pin on you,” Strand said to Cosgro.

After Millar was arrested in February of 2024 for Rothe’s death, Cosgro changed her story again. Called to speak on the record with Hanks in the spring of 2024, Cosgro backed off the length of time Millar supposedly kneed Rothe, telling Hanks it was down to seconds.

Cosgro’s 2024 interview with Hanks resulted in a disciplinary letter for her policy violations during the room extraction and for lying during the subsequent investigations. Cosgro was demoted to a counselor, but remained employed by the DOC. Strand read from the letter during the trial, stating that Cosgro “demonstrated significant inconsistencies in [her] statements” in the Rothe investigation.

But the fact Cosgro had changed her story in 2024 had been held back from Millar’s defense team for at least a year. It wasn’t until days before the trial was originally set to start in March that thousands of pages of evidence was finally handed over.

Among the evidence the DOC originally held onto were emails demonstrating that Hanks herself had been told by the Attorney General’s Office in 2024 to not conduct interviews with Cosgro or any of the other witnesses.

This article first appeared on InDepthNH.org and is republished here under a Creative Commons license.