DALLAS (CBSDFW.COM) — After narrowing down 400 people to 12, the jury for the Amber Guyger trial has been chosen.

Thursday night, the judge allowed the remaining pool of 220 potential jurors to go home. But by now, 16 of them should have received a phone call notifying them they’ve been selected to serve — 12 as jurors and 4 as alternates.

The first time this jury will sit together will be the first day of Guyger’s trial, which is scheduled for Sept. 23.

The former Dallas police officer — who shot and killed unarmed man Botham Jean in his apartment last year — was at the courthouse today, watching as the prosecution and defense questioned potential jurors.

When polled by a prosecutor, 10 said they could not — under any circumstances — find her guilty for the murder of Jean. And when asked by the defense, another half dozen expressed skepticism of her account that she mistook his apartment for her own, and killed him thinking he was an intruder.

These answers disqualified people who showed an inability to be impartial.

However, the selected jurors understand this is a “big trial” and when given the chance, they asked about their security, their ability to remain anonymous and how to prepare for sequester.

To that, the judge has strongly suggested they will be put up in a hotel and kept to themselves for the duration of the trial — which was estimated to last around two weeks.