The 66-year-old actor faced his first day in front of a jury on Wednesday in New Mexico, and stands accused of involuntary manslaughter after cinematographer Halyna Hutchins, 42, was killed on the set of neo-Western movie 'Rust' in New Mexico in 2021.
Looking distressed and tired, at one point he put his hand on his forehead as jurors were shown body cam footage captured by Santa Fe County Sheriff's deputy Nicholas LeFleur - who was called as the first witness in the case.
The clip showed Halyna lying on her back following the shooting, with tubes coming out of her body as medical teams tend to her.
Deputy LeFleur is heard saying: "One female shot in the chest, male shot in the stomach."
'Rust' director Joel Souza, 51, who was also injured in the fatal shooting, can be heard shouting in pain and thrashing his legs around.
One person is heard saying about the filmmaker: "He's good. he's got a (inaudible) shoulder blade (wound.)"
A woman helping Hutchins to breathe says: "Halyna deep breath, deep breath there you go. Deep breath Halyna. Jesus."
Film crew staff and emergency workers could be seen in the footage hoisting mother-of-one Halyna up on a stretcher.
Father-of-eight Alec was also comforted by his wife Hilaria Baldwin, 40, in court.
'Rust' armourer Hannah Gutierrez-Reed, 26, has already faced trial over the shooting and was found guilty on the same charges in the same court.
In her opening statement, prosecutor Erlinda Johnson said Alec had "violated the cardinal rules of firearm safety" and was "reckless" on set.
She added he also had requested the biggest gun available after he arrived on the set in in October 2021.
Alec's attorney Alex Spiro stressed in his opening statement the star operated as actors normally do on a movie set involving weapons and said his client had committed no crime.