When asked to give to a highly worthy cause (to help emotionally disturbed children), the donation rate trebled if donors were offered a product in exchange for their gift.

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Mr. Browne said the suspect appeared to be emotionally disturbed to some of the witnesses and it was unclear what kind of conversation he had engaged in with the victim.

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The incident appeared to echo one of the city's most notorious subway attacks: the 1999 killing of Kendra Webdale, who was pushed in front of a train by an emotionally disturbed man.

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He spent several hours in a New York hospital in October after police responded to an early morning call about "an emotionally disturbed person" at the Plaza Hotel, a law enforcement source said at the time.

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Later, as a defense attorney in South Carolina, Bruck recruited Clarke to help him defend Susan Smith, the emotionally disturbed mother who in October 1994 strapped her two boys into her car and let it roll into a lake, drowning them.

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