The police officer who fatally shot Philando Castile during a traffic stop in Minnesota last year said he opened fire, in part, because he smelled marijuana—and assumed that Castile had been smoking in front of his four-year-old daughter.

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Dashcam video of the shooting, released on Tuesday, showed just 30 seconds passed from the time that Officer Jeronimo Yanez approached the vehicle and when he opened fire. But in that short time, Yanez said he began fearing for his life due to his suspicion that Castile had recently consumed cannabis in his daughter's presence, as well as Castile's admission that he had a legally registered firearm, according to court transcripts from his trial in July.

"I thought I was gonna die and I thought if he's—if he has the guts and audacity to smoke marijuana in front of the five-year-old girl and risk her lungs and risk her life by giving her secondhand smoke, and the front seat passenger doing the same thing, then what—what care does he give about me?" Yanez said.

The fact that the officer allegedly smelled marijuana, and later found traces of cannabis in the vehicle, were a point of focus in the defense during Yanez's trial. "Lawyers said [his alleged marijuana use] may have slowed down Castile’s response to Yanez’s commands, which made him even more suspicious," The Atlantic reported.

But Yanez's testimony about secondhand marijuana smoke is another issue. While studies have found evidence that inhalation of secondhand smoke derived from cannabis can be harmful, the officer's account plays into a misconception that marijuana users are inherently dangerous. Would Yanez have feared for his life and had the same reaction if he smelled smoke from a recently lit cigarette?

Researchers have found that marijuana users are no more likely to exhibit violent behavior than non-users. In 2014, a study published in the journal Psychology of Addictive Behaviors determined that cannabis use among couples was associated with lower rates of domestic violence, for example.

In any case, Yanez prevailed in his trial and was acquitted of all charges in the shooting. Whether his stated concerns about Castile's alleged marijuana use influenced the jury's decision is uncertain, but what's clear is that it certainly didn't help the victim's case—despite the defense's reliance on unfounded beliefs about the risks that users pose.