Riley Strain's stepdad opens up about family's difficult conversations as Nashville search intensifies

Over 10 days into the search for missing college student Riley Strain, his family said they're starting to have difficult conversations.

"Put yourself in our shoes," Strain's stepfather, Chris Whiteid, told ABC News on Wednesday. "Your family, your brother, your sister -- they've been missing for almost two weeks."

"Everybody knows it, everybody's thinking it -- those conversations are starting to happen," he said. "It's not what we want. And I understand that people want to know what we're feeling -- we're feeling frustrated, we're feeling hurt, we're feeling depressed."

"Nobody knows what happened to Riley," he said.

Strain, a 22-year-old senior at the University of Missouri, went missing on March 8 after a night out in Nashville.

Strain and his Delta Chi fraternity brothers were in Nashville for their fraternity formal and went out in the city's Broadway area.

Whiteid said Strain spoke to his mom multiple times a day. On the night of March 8, Whiteid said Strain FaceTimed his mom from a bar and didn't sound intoxicated.

Strain and his mom exchanged more texts after the FaceTime call, Whiteid said. The last text Strain sent to his mom that night was, "I love you."

Surveillance cameras and police body cameras captured Strain's last known movements from about 9:30 p.m. to 10 p.m.

Police released this body camera video of Strain speaking to a police officer around 9:50 p.m. The officer asked how he was doing, and Strain, walking alone, responded, "I’m good, how are you?"

Whiteid said Strain sounded like his usual polite self in that interaction with the officer.

"Why he didn't ask for help, I can't answer," Whiteid said. "It makes no sense."

Police said there is no evidence of foul play.

On Sunday, Strain's bank card was found on the embankment between Gay Street and the Cumberland River, near Riverfront Park, police said.

Authorities have been searching by foot, by drone and by boat, including using boats with sonar equipment, according to police.

The United Cajun Navy has also arrived in Nashville to help and is organizing volunteers. David Flagg of the United Cajun Navy said they're searching the river and are putting together a "structured and organized ground search."

And the search is now stretching beyond Nashville, with authorities on Wednesday shutting down a dam to look through debris about 30 miles downstream from the riverbanks where Strain was last seen, according to Nashville ABC affiliate WKRN.

"We feel very confident with everything that's moving forward," Whiteid said of the police investigation, city support and volunteer searches. "There's not a playbook we can go by when, you know, something like this happens, so the more experienced people you can have in your corner, the better."

Whiteid said that he believes "somebody's seen something, somebody knows something."

"They just have to realize they need to share that information with us," he said.