(CNN) The mother had been in a store in Arizona for about 30 minutes, she told police, when she realized she'd left her 5-month-old in her hot car, bodycam footage of the June incident shows.

Stacey Holly, 37, tearfully told an officer in Goodyear that she accidentally left her daughter in the back seat as she, her sister and her 6-year-old daughter went into Target to shop, according to the recording.

She called 911 when she realized what she'd done, CNN affiliate KTVK reported. It was about 100 degrees Fahrenheit that day, police have said.

The 5-month-old ended up being OK, police said.

"I don't know, I honestly don't know how it happened. I don't ... I'm freaking out, I'm sorry. I just, I don't know how it happened. Like, how do you forget your baby?" Holly says to an officer during an interview, police footage shows.

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