Samantha Murowski took the witness stand to testify against her ex-boyfriend Micah Patterson, who's been charged with sexually assaulting and murdering her four-month-old baby girl Aubrey.
In the first day of the jury trial, Murowski testified for hours going over the timeline of the night her baby died.
Police say Patterson, a former sailor, was watching over baby Aubrey in January of last year.
While he was babysitting her, Aubrey stopped breathing and an autopsy showed she had injuries to her neck, stomach and chest.
In addition to Murowski's testimony, several others took the stand all while the mother tearfully watched.
An officer who responded to the apartment the night Aubrey died said Patterson showed no emotion as they inspected the scene.
And an inmate who served time with Patterson told the jury he confessed to sexually assaulting the 4-month-old then smothering her with a pillow to stop her from crying.
Also testifying today was a forensics expert who said she didn't find any foreign DNA on the baby.
Patterson is also charged with object sexual penetration and felony child abuse and neglect.
The jury is expecting to hear from 14 witnesses between today and Thursday.