That is unclear, but it has been a complex case with each side presenting a huge amount of expert testimony.
In a note to the judge on Thursday, the panel indicated one juror wasn’t following guidance on reasonable doubt.
Under US law, a jury must unanimously believe “beyond a reasonable doubt” that someone is guilty in order to convict them of a crime.
The designation is the strictest standard in the US legal system. It places the burden on the government to prove that the accused is guilty, and not the accused to prove their innocence.
Clancy’s lawyer indicated that sole juror was holding up the proceedings and causing the deadlock. He asked the judge for that juror to be removed.
But the judge denied his request and the next day, he officially declared a mistrial.
The identities of the nine women and three men on the jury has not been made public, and the judge banned any photographing or filming of them to retain their anonymity.
But once a case is over, a juror can choose whether or not to speak publicly about the case and their deliberations.
Following other high-profile trials, jurors have in some instances come forward to discuss the case, even writing books or doing media interviews.
So while it remains unknown to the public what has gone on behind closed doors, more could be revealed in the coming days or weeks.
If you are suffering distress or despair and need support, you could speak to a health professional, or an organisation that offers support. Details of help available in many countries can be found at Befrienders Worldwide. www.befrienders.org.
In the UK a list of organisations that can help is available at bbc.co.uk/actionline
