In the early hours of February 4, 1999, an unarmed 23-year-old Guinean student named Amadou Diallo (born September 2, 1975) was fired upon with 41 rounds and shot a total of 19 times by four New York City Police Department plainclothes officers: Sean Carroll, Richard Murphy, Edward McMellon, and Kenneth Boss.

The four officers, who were part of the Street Crime Unit, which had expanded in size under mayor Rudy Giuliani, were charged with second-degree murder and acquitted at trial in Albany, New York.

He was born in Sinoe County in Liberia on September 2, 1975,[2] while his father was working there, and while growing up followed his family to Togo, Singapore, Thailand, and back to Guinea.

According to his family's lawyer, he sought to remain in the United States by filing a political asylum application, falsely claiming that he was from Mauritania and that his parents had been killed in fighting.

At about 12:40 a.m., officers Edward McMellon, Sean Carroll, Kenneth Boss, and Richard Murphy were looking for a serial rapist in the Soundview section of the Bronx.

Nonetheless, the Diallo shooting led to a review of police training policy and switching away from the use of full metal jacket (FMJ) bullets.

In 2003, Diallo's mother published a memoir, My Heart Will Cross This Ocean: My Story, My Son, Amadou, with the help of author Craig Wolff.

Bronx borough president and mayoral candidate Fernando Ferrer, who had protested against the circumstances of the killing at the time, was criticized by the Diallo family and many others for telling a meeting of police sergeants that although the shooting had been a tragedy, the officers had been "over-indicted".

[25][26] In April 2021, Diallo's mother was interviewed about her reaction to the conviction of Minneapolis police officer Derek Chauvin for the murder of George Floyd.