ST. PAUL — A Minnesota police officer who fatally shot a black motorist told a fellow officer afterward that he didn’t know where the motorist’s gun was, according to audio played Tuesday for jurors.

The audio is key evidence in Officer Jeronimo Yanez’s manslaughter trial in the death of Philando Castile last July in a St. Paul suburb. Prosecutors argue Yanez acted unreasonably; his attorneys say he feared for his life and made a split-second decision in the presence of a gun.

Yanez and his partner had stopped Castile over a broken taillight when the 32-year-old elementary school cafeteria worker informed Yanez that he was carrying a gun. A little over a minute later, Yanez had fired seven shots and Castile was mortally wounded.

The shooting was one in a string involving police and black men nationally, and drew added attention because Castile’s girlfriend streamed the aftermath on Facebook as he lay dying. Castile’s family claimed he was profiled because of his race.

The audio of the encounter came from squad car video, which does not show Yanez but picks up his voice from his body microphone. He tells his partner that Castile went to grab something and that Castile’s grip seemed wider than a wallet would be.

“I don’t know where the gun was,” Yanez says. “He didn’t tell me where the … gun was,” he adds, using an obscenity.

The officer who was with Yanez, Joseph Kauser, testified that Yanez subsequently told him he had seen a gun on Castile, who had a permit for the weapon. Kauser said he didn’t see a gun in Castile’s car or anywhere else from his vantage point on the passenger side of the car. But Kauser also said he was watching Castile’s passengers — his girlfriend Diamond Reynolds and Reynolds’ then-4-year-old daughter — rather than the driver.

Yanez, 29, who is Latino, is also charged with two counts of dangerous discharge of a firearm for endangering Reynolds and her daughter.

Earlier Tuesday, Reynolds cried as squad car video, her Facebook video and still images of Castile were shown. Asked why she took out her phone and started recording, Reynolds said she feared for her own life.

“Because I know that the people are not protected against the police,” Reynolds said. “I wanted to make sure if I died in front of my daughter that people would know the truth.”

Defense attorneys also have argued that Castile had smoked marijuana that day and that it affected his actions. Toxicology reports show Castile had THC — the high-producing component of marijuana — in his system.

Reynolds acknowledged under questioning from defense attorney Earl Gray that she and Castile smoked regularly. She also acknowledged marijuana was in the car at the time.

Gray cited a Facebook video Reynolds posted showing her and Castile smoking pot in a car with her daughter in the back seat the day before the shooting, but Castile’s use of marijuana the day of the shooting wasn’t addressed.

In his testimony, Kauser discussed the reason for the traffic stop and the way the officers handled it. He said that even though Yanez told him that he thought Castile resembled a suspect in a recent armed robbery, there was not enough concern to do a felony traffic stop — in which all occupants are ordered out of the car with their hands up before officers approach. Instead, Kauser said, it was handled as a “stop and ID.”