NEW YORK (CBSNewYork/AP) — New York City prosecutors have dropped a harassment case against the sister of the Boston Marathon bombers.

The Manhattan district attorney’s office said it had “significant” questions about the credibility of the woman who accused Ailina Tsarnaeva of making a bomb threat against her last summer in which she allegedly said, “I know people that can put a bomb where you live.”

Tsarnaeva wasn’t in court as the case was dismissed, and her lawyer didn’t immediately return a call afterward. The lawyer, Susan Marcus, has said Tsarnaeva denies making the threat and was “an easy target” for an “uncorroborated claim.”

The development came as some of Tsarnaeva’s relatives testified in the death penalty phase of her brother Dzhokhar Tsarnaev’s federal trial in Boston. Tsarnaev, 21, was convicted last month of 30 federal charges in the April 2013 bombing that killed three people and injured over 260.

His lawyers admitted he took part in the bombings but said he was induced to do it by older brother Tamerlan Tsarnaev, who was killed in a gun battle with police during the subsequent manhunt.

Tsarnaeva, meanwhile, was accused of harassing a woman who previously had a romantic relationship with her husband. According to a criminal court complaint, Tsarnaeva, 24, of North Bergen, New Jersey, told the woman by phone Aug. 25 to leave him alone and made the bomb threat. At a court date last fall, prosecutors called it an apparent reference to her brothers.

Tsarnaeva, a mother of two, told police she asked the woman to stop contacting her husband because she had been texting him about “what she saw about us on TV,” according to a statement she gave police. She said the woman started screaming at her, so she hung up.

Prosecutors noted Monday that they felt police had probable cause to arrest Tsarnaeva; a judge also found in January that there was enough evidence for the case to proceed. But prosecutors said the misdemeanor case fell short of proof beyond a reasonable doubt after they interviewed the accuser and Tsarnaeva, spoke to other witnesses and reviewed phone records.

While facing the New York charges, Tsarnaeva pleaded guilty in Boston in November to misleading a police detective during a 2010 counterfeiting investigation. She was then freed of court supervision there after avoiding further legal trouble for 30 days.

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