When an Iowa woman ventures out to spend a summer afternoon unwinding on the banks of a South Dakota river, she's ambushed by an opportunistic predator.

Investigators believe they're facing the rarest type of murder, a true stranger killing in this episode of Last Seen Alive.

... Alive. Thanks for listening to Last Seen Alive.

I'm your host Leah, crime analyst by day, and true crime storyteller by night.

And as always, I'm your co-host Scott.

A quick heads up. This episode contains mention of the subject of sexual assault.

We won't go into any graphic detail, but still, please listen with care.

Alicia Hummel was last seen alive on June 1st, 2015.

She was 29 years old at the time and lived in Sioux City, Iowa.

She was a longtime resident of Sioux City, where she'd grown up in her grandparents' care.

She was a kind, adventurous, and communicative person. Her friends and family

members have consistently described her as bubbly. As a young adult, she'd attended South Dakota

State University, earning a bachelor's degree in human development and family studies. From there,

she'd gone on to work as a preschool teacher. She had plans to continue her education in the future to earn a master's degree, but meanwhile, she truly enjoyed her job.

At the preschool where she worked, she taught early Head Start for infants and toddlers.

She loved kids, so the job suited her.

By June of 2015, she'd been working there for two years and had just recently accepted

a job offer for another position. The time period between the conclusion of her old position and the

start of her new one would be about a month long, so she'd have four weeks to herself to enjoy the start

of summer. Naturally, she was excited by this. It would give her the chance to do

things she loved but had put on the back burner in order to devote herself to her work. In addition to

music, dancing, and scrapbooking, Alicia deeply loved the outdoors. In particular, she enjoyed fishing,

...