YOUNGSTOWN — Dawn Cantalamessa, who has prosecuted high profile murder cases in Mahoning County Common Pleas Court for many years, has resigned as assistant prosecutor after a judge removed her from a case last month.

Mahoning County Prosecutor Paul Gains said today Cantalamessa’s “one-line” resignation letter did not give a reason for her departure but said it takes effect immediately.

Gains placed her on paid administrative leave pending an internal review after Judge John Durkin of Mahoning County Common Pleas Court removed Cantalamessa from the Lavontae E. Knight aggravated murder case, citing her “careless indifference to ascertaining the truth” regarding evidence in the Knight case and making a false statement to the court.

Cantalamessa, of Warren, indicated in May she was considering a run next year for judge of Trumbull County Common Pleas Court to replace Judge W. Wyatt McKay, who cannot run for another term.

Attorney David Betras, who represents Knight, filed a motion in the case asking for Cantalamessa to be removed from the case or for charges to be dismissed against Knight, citing what Betras called “deceitful” behavior by Cantalamessa.

Betras provided documents and other information to show that more than two years went by between the time an eyewitness failed to identify Knight from a photo lineup as being involved in the killing of Josh Donatelli, 26, and when Betras learned about the lineup 10 days before the case was due for trial.

Prosecutors have said Cantalamessa did not turn over that information because she didn’t know it existed. A Youngstown police detective later testified at a hearing that he turned over the evidence to the prosecutor’s office but did not remember telling Cantalamessa about it.

The judge’s ruling faulted Cantalamessa for failing to “periodically and regularly review her case file” and that if she had called the detective about evidence in 2019 or 2020, she would have discovered that evidence helpful to the defense never made it to Betras as required.

“This failure, especially given the defendant’s repeated requests for additional evidence concerning the eyewitness, can best be characterized as a careless indifference to ascertaining the truth,” the judge stated in the ruling.

The judge also found that Cantalamessa made a false statement during a Dec. 3, 2019, hearing because she told Durkin and Betras that co-defendant George Gutierres never identified Knight as being the shooter in the killing.

The judge refused to dismiss the charge against Knight, who currently has no trial date. The last trial date was Aug. 9, but it was canceled. A pretrial is set for 11 a.m. Aug. 31.

erunyan@vindy.com