Ms. Reynolds said Mr. Castile embraced her and became “a father figure” to her young daughter, Dae’Anna, now 5. He would read the girl books and make sure she had a healthy breakfast. Jurors saw a photo of Mr. Castile and Dae’Anna celebrating her birthday at the Mall of America.

“He was a friend to her,” Ms. Reynolds said. “He was a role model.”

On the day of the shooting, Ms. Reynolds said Mr. Castile went to work, then got his hair fixed. Separately, Ms. Reynolds took public transit to drop her daughter off at preschool that morning and traveled to her job at a dollar store. Later that day, Ms. Reynolds said she and her sister smoked marijuana, picked up Dae’Anna from preschool and met up with Mr. Castile in the evening to go grocery shopping.

Earl Gray, a lawyer for Officer Yanez, questioned Ms. Reynolds at length about her marijuana use. Ms. Reynolds said she and Mr. Castile smoked marijuana daily, and had done so for years. She admitted that there was marijuana in the car at the time Officer Yanez pulled them over, but she said they had not been smoking.

Mr. Gray also pointed out what he said were inconsistent details in Ms. Reynolds’s past statements about the case. Ms. Reynolds said she was being honest. Lawyers did not mention felony assault charges Ms. Reynolds is facing in connection with an alleged hammer attack this year. That case is still pending.

In court on Tuesday, Officer Joseph Kauser, Officer Yanez’s partner, testified that he did not see a gun in Mr. Castile’s car, did not smell the burned marijuana described by Officer Yanez and was not alarmed by the situation until his colleague started shooting.

“I did not feel threatened at that point from where I was standing,” Officer Kauser said of the moment right before the shooting.