By Madison Park and Brad Parks

CNN

ST. PAUL, Minnesota (CNN) -- Diamond Reynolds, who saw a police officer fatally shoot her fiancé, Philando Castile, during a traffic stop last summer, will return to the witness stand on Tuesday.

She testified briefly on Monday, shortly after the opening arguments in the manslaughter case of the officer Jeronimo Yanez. She cried on the stand after seeing a photo of Castile, whom she described as a kind man.

Reynolds had been in the passenger's seat and her 4-year-old daughter in the backseat when Yanez pulled over Castile on July 6.

During their brief encounter in Falcon Heights, Minnesota, Castile told Yanez he had a firearm. Yanez warned Castile not to reach for it. Seconds later, Yanez fired seven shots -- five of them struck Castile, killing the Montessori school cafeteria worker, according to prosecutors.

Castile's last words were, "I wasn't reaching for it," insisting that he wasn't reaching for his registered handgun, according to a transcript presented in the criminal complaint against Yanez.

The shooting spurred immediate coverage as Reynolds started a live stream on Facebook. The video quickly went viral, sparking protests nationwide and renewing criticism of the use of deadly force by police, especially against African-American men.

Castile had a permit to carry a firearm in his wallet.

He carried a gun because of crime in the neighborhood, as there had been two killings along with drugs and prostitution, Reynolds testified in court.

"He always had it for protection for himself and protection for his family," she said.

Opening arguments tell two different stories

Yanez faces charges of second-degree manslaughter and two felony counts of dangerous discharge of a firearm, for endangering Reynolds and her daughter in the backseat. Prosecutors say one of the bullets Yanez fired pierced the front seat and came very close to the girl, and that another bullet, that could have hit Reynolds, was blocked by the front seat armrest.

For the first time, prosecutors showed the police dashcam video of the shooting to the 12 jurors and three alternates.

During opening arguments, prosecutors said Yanez was negligent by not giving Castile clearer direction when he learned Castile had a weapon.

"He didn't tell him to freeze" or put his hands up, said Assistant Ramsey County Attorney Richard Dusterhoft. "Officer Yanez's actions led to Philando Castile's death."

A portrait of the officer

Meanwhile, the defense offered a different perspective during opening statements.

Castile had ignored the officer's commands and reached for his weapon when he was instructed not to do so, said Paul Engh, Yanez's defense attorney.

Engh told the court Castile's fate was a result of his inability to follow orders and that he was high on marijuana, saying that THC had been found in his system.

The defense lawyer also spoke of Yanez and his upbringing.

His father came from Mexico and worked as a migrant farmer. When Yanez became a police officer, it was "the best day of Yanez' life," the attorney said. Engh also pointed out his father, brother and wife who were sitting in the front row.

He said Yanez had learned about the reasonable use of force and had never been disciplined during his time on the police force.

Reynolds: Castile was kind

On Monday, Reynolds testified for about 30 minutes before the court went into recess for the day.

During her testimony, she began crying when shown a photo of Castile and her daughter, who is now 5. Although Castile was not the girl's father, he cared for the child and helped provide for her, Reynolds said. He was kind and had a soft voice, she said.

The couple had sometimes gone to police barbeques to "show support" and she said Castile had no animosity for police.