
Donatila O’Mahony, pictured in a mugshot provided by the Suffolk County DA’s Office
A 43-year-old Long Island woman convicted in the “cold-blooded” execution murder of a 69-year-old homeowner to forge his will and take up residence on the property will spend a quarter century to life in her “new home”: Prison.
Prosecutors in the office of Suffolk County District Attorney Raymond A. Tierney said, and jurors were persuaded, that Donatila O’Mahony of Central Islip asked a friend to provide her with a gun she later used to shoot Lee Pedersen once in the back of his head at his Aquebogue home in March 2020. Though O’Mahony reportedly insisted upon her innocence and claimed that she did not kill a man she regarded as “one of the best friends” she “ever had,” jurors believed prosecutors when they said that the case was as bad and clear-cut as it appeared at first glance.

Lee Pedersen (photo used with permission of Rough & Tumble Engineers)
“Prior to the murder, in 2019, O’Mahony asked a friend in New Jersey to purchase an Sig Sauer 9mm handgun, which she would later use to kill Pedersen. On the night of the murder, she borrowed that same friend’s car, which was captured on video surveillance in the area of Pedersen’s home,” prosecutors said in a press release describing the facts of the case. “That car was also captured on video surveillance returning to O’Mahony’s home several hours after the murder.”
The friend was later identified as 76-year-old George C. Woodworth, who testified for the prosecution at O’Mahony’s trial and admitted to his role in both providing the murder weapon and to helping getting rid of it, along with other evidence. Woodworth also admitted to letting O’Mahony use his car.
“When O’Mahony later returned to her own home, she asked her friend from New Jersey to dispose of several items, including the Sig Sauer 9mm handgun he had purchased for her, ammunition, and clothes. O’Mahony’s friend destroyed the handgun and disposed of the clothes, but kept the plastic bag of ammunition in his home in New Jersey. The bag of ammunition was subsequently recovered by police and swabbed for DNA,” prosecutors said. “The Suffolk County Crime Laboratory then conducted a forensic analysis which revealed the presence of both O’Mahony’s and Pedersen’s DNA on the swabs.”
New York State court records indicate that Woodworth’s sentencing is scheduled for April 10, having pleaded guilty plea to a criminal solicitation charge in the case.
Prosecutors said that O’Mahony’s attempt to forge Pedersen’s will and get away with was a failure, as the victim’s real will said nothing about the defendant being entitled to the man’s home upon his death.
“This was a cold-blooded killing fueled by greed, treachery, and the complete disregard for Lee Pedersen’s life, all in order to steal the victim’s home,” DA Tierney said in a statement. “The only new home this defendant will be living in as a result of her actions, is prison.”
Jurors ultimately convicted Mahoney of the charges on Jan. 4, and O’Mahony was sentenced to serve 25 years to life in prison Thursday. Prosecutors said must also serve a consecutive sentence of 2 1/3 years to 7 years for forging the will and attempted grand larceny.
According to those who knew him, Lee Pedersen was a wizard when it came to antique engines. The lifetime member of Rough & Tumble Engineers Historical Association in Pennsylvania was remembered as a “friendly man” and stepfather who “had come to many of the Antique Steam and Gas shows around the US and was a collector of antique engines.”
Pedersen “worked on antique engines and kept the 1930s cottage his parents previously owned in meticulous shape,” the group added.

Lee Pedersen (photo used with permission of Rough & Tumble Engineers)
“He is greatly missed by friends, family and the antique gas engine community he helped shape,” an obituary also said of Pedersen.
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