Medical Examiner Dr. Andrew Baker said Castile was hit twice in the heart, which ended up being the fatal two shots.
Yanez, 29, who is Latino, is also charged with two counts of risky discharge of a firearm for endangering Reynolds and her daughter.
Reynolds, dressed in black hair, appeared confident on the stand Tuesday morning.
A jury of 15, including three alternates, is hearing the case in Ramsey County District Court.
"I felt broken, hurt, confused, lost", Reynolds said.
"He always had it for protection for himself and protection for his family", she said. But first they stopped off at her house to smoke a joint, then picked up 4-year-old Dae-Anna from day care.
Noble countered that Yanez used "qualifiers" to talk about what he saw Castile reach for that night, such as "a dark object" or something that required Castile to form a "wide grip".
Defense attorneys say Castile was stoned, contributing to his death. After the shooting, officers said, they found marijuana in a Mason jar in the auto.
The case garnered attention when Reynolds livestreamed the aftermath of the shooting on Facebook. Courtroom watchers cried too.
On July 6, Yanez pulled over Castile, saying he looked similar to a robbery suspect. She said it was. Reynolds streamed the aftermath on Facebook.More news: European Central Bank revises upwards 2017-2019 euro area economic growth forecast
She said she also feared for her daughter's safety.
The tense exchange between Reynolds and the defense peaked near its conclusion when Gray asked Reynolds about a GoFundMe campaign started in her name. "He has a blue tie, in a suit today and glasses". She turned her head away and wept. Recent killings in the neighborhood, along with drugs and prostitution, spurred Castile to carry a gun for self-defense, she said. The autopsy found THC in Castile's blood.
"People are not protected against the police", she replied.
"Please don't tell me he's gone!" she screams.
Gray also pointed out changes in Reynolds' story about who purchased the marijuana found in Castile's vehicle after the incident - first saying it was hers, then later that it belonged to both her and Castile and, finally, that Castile had purchased it.
When Reynolds took the stand Monday, she wept as soon as she saw a photo of Castile.
The jury is selected and opening statements were given. He had been reaching for his ID in his back pocket when he was shot, Reynolds said. If someone else was going to die, she wanted evidence.
To fill in the gaps, prosecutors called former St. Anthony Officer Joseph Kauser.
Castile, 32, ignored the St. Anthony police officer's commands and reached for his weapon when he was instructed not to do so, Engh said.
Brad Parks reported from St. Paul. Bloomington, pop. 86,000, southwest of the state capital, is Minnesota's fourth-largest city.
He also acknowledged that he and Yanez had known each other since 2006 and were good friends. Yanez was interacting with Castile on the driver's side at the time. Yanez told him not to reach for it. Seconds later, Yanez opened fire.More news: Apple updates its iPad, iMac and MacBook ranges
In an audio recording played in court, Yanez said he was stopping a vehicle with two occupants to check their identifications because one of them looked like a robbery suspect based on his "wide-set nose".
When Kauser arrived, he said, it was "light enough to see but the sun was setting". Yanez shot Castile after the motorist told him he was carrying a gun.
Kauser said that if he knows the suspect has a gun, he asks them where it is, and asks them to keep their hands in his view, such as on the dashboard or steering wheel.
On Tuesday, the jury heard audio from squad auto video, which does not show Yanez but picks up his voice from his body microphone.
"I didn't feel threatened at that point from where I was standing", he said.
"I ask where it is", Kauser said.
Officers who testified - Kauser and a Roseville police officer who responded to the shooting - also were asked to weigh in on the reasonableness of Yanez's actions.
Yanez said that Castile was buckled into his seat, and that he had told Castile "not to reach for it".
Defense attorney Earl Gray pointed out inconsistencies in Reynolds' version of what happened during his cross-examination. He said that Kauser had said that Yanez had told him that "he observed a firearm", during Kauser's initial statement to the Minnesota Bureau of Criminal Apprehension. "I trust him as a partner, and he did what he's supposed to do in that situation".
(St. Paul MN-) The trial of Officer Jeronimo Yanez continues in St. Paul today after an emotional day of testimony Tuesday. As he bled, the officer kept his gun pointed into Castile's vehicle.
On Wednesday, Garfield explained the trajectory of Yanez's bullets.More news: Nursery Worker In East London Slashed Amid 'Allah' Cries
- Congress Joins Netanyahu in Celebrating 50 Years of a Free Jerusalem
- Is Trump tweeting during the Comey hearing? No, but everyone else is
- Ben McKenzie & Morena Baccarin Reportedly Get Married On An Extra Special Day
- Trump doesn't tweet during Comey testimony
- Saudi FM: 'Brother State' Qatar Must Act to End Crisis
- 'Trump fired me because of Russian Federation investigation': Comey
- Lies: Comey says Trump administration fired him over FBI-Russia investigation
- No country has the right to intervene in Qatar foreign policy: FM
- Trump again touts infrastructure plan during campaign-style speech
- ECB president sees inflation still subdued