(Photo: AP Photo/Family Photo via The Detroit News)

DETROIT (AP) — A judge Tuesday declared a mistrial after jurors failed to reach a verdict in the trial of a Detroit police officer who fatally shot a 7-year-old girl.

Wayne County Judge Cynthia Gray Hathaway dismissed jurors about an hour after urging them to keep working Tuesday. The jury sent three notes, the last one indicating it still couldn't reach a unanimous verdict on the third day of deliberations.

Joseph Weekley, a member of an elite squad, was charged with involuntary manslaughter in the death of Aiyana Stanley-Jones.

Prosecutors said Weekley neglected to control his submachine gun as his black-clad, masked and armed unit stormed the home in the hunt for a murder suspect in May 2010. They did not accuse him of intentionally shooting the girl.

Police threw a stun grenade through a window, and Weekley was the first officer through the door. Aiyana was shot in the head just a few seconds later as she slept on a couch.

Weekley said he pulled the trigger during a struggle with the girl's grandmother, but Mertilla Jones denied interfering with the gun.

Weekley's unit was being shadowed by a crew from the reality TV show, "The First 48," a police reality show on A&E Networks.

Earlier Tuesday, loud voices could be heard through the closed door of the jury room. Reporters and spectators awaiting a verdict were then ordered out of the courtroom.

The jury could have convicted Weekley of involuntary manslaughter, a lesser crime or cleared him of all charges.

The judge listed several factors for the jury to consider on the involuntary manslaughter charge. To convict, the jury must find he acted in a "grossly negligent manner" and willfully disregarded possible injuries to others by failing to control his submachine gun.

BET National News - Keep up to date with breaking news stories from around the nation, including headlines from the hip hop and entertainment world. Click here to subscribe to our newsletter. 

Get ready for the BET Experience, featuring Beyoncé, Snoop Dogg, R. Kelly, Erykah Badu, Kendrick Lamar and many more. Go here for more details and info on how to buy tickets. Sign up now to attend free film screenings, celebrity basketball games and more.