Story highlights The 30-year-old doctor in residency failed to show up for work on December 6

Investigators searched but came up empty

Now, they are poring through 20 minutes worth of video

They want to know who is Patrick talking to in the video

Three weeks ago, Teleka Patrick disappeared.

The 30-year-old doctor in residency failed to show up for work on December 6 in Kalamazoo, Michigan. The night before, police 100 miles south in Indiana found her car abandoned but not crashed in a ditch off busy I-94.

Investigators searched but came up empty.

"We looked everywhere," Sgt. Rick Strong of the Indiana State Police told CNN.

Now investigators have more potential evidence, about 20 minutes worth.

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Videos provide clues

Surveillance and home videos uploaded to YouTube provide clues about Patrick's movement in the weeks, days and hours before she vanished.

In a different context, the YouTube videos might be considered sweet or romantic. They feature Patrick talking, cooing and singing to someone unnamed and apparently unknown.

Patrick's mother told CNN she wasn't aware of any romantic relationship her daughter may have had. But the videos have an intimate feel to them.

"Hi, baby," Patrick says in one. "I am just coming to you to say 'hi' and tell you about my day."

In another video, Patrick shows a table set for two with omelets and pancakes.

"If you were here, this is what would be your plate," she coos.

The two videos were posted in early November. It's not completely clear why they only drew attention now.

A third video to surface comes from a local hotel in Kalamazoo. That's where Patrick went on the night of December 5, just hours before police found her car in that ditch.

At a little past 7:30 p.m., Patrick, dressed all in black, showed up at a Radisson hotel not far from the hospital where she worked.

She spent around 10 minutes talking with employees at the reception desk but ultimately left.

There's no audio on the video, and it's not clear why Patrick failed to book a room.

But at 7:48 p.m., she strode across the hotel's tiled floors, out the door and onto a hotel shuttle bus.

Those images provide the last known picture of Patrick.

Friends, family shocked

Patrick's disappearance has, from the beginning, drawn shock from many corners.

Her family says Patrick, who had just moved to Michigan, bought a plane ticket to come visit them for the holidays in Florida.

Her colleagues called her "part of our family of medical professionals."

And CNN's audience posted by the droves on iReport asking for coverage in the hopes that more information and coverage would propel the case forward.

The young doctor was described in comments as "wonderful," "beautiful" and "talented."

The newly discovered videos add to the swirl of questions surrounding this case.

Investigators have said they have no evidence of foul play, but they also don't have conclusive evidence that Patrick's movements on December 5 were voluntary.

Police brought out dogs to track Patrick's scent. They led investigators the 30 or so feet out of the ditch where Patrick's car rested to the highway. There, the trace went cold.

"We have scoured, searched and looked at everything we could possibly look at -- all the exits, all the businesses, all the hotels," Strong said. "We posted fliers; we talked to neighbors (who live near the highway). We did a full-blown, on-the-ground search in the wooded area north of where the car was."

Carl Clatterback, a private investigator hired by Patrick's family, told CNN that investigators are looking into the videos. A central question: Who is Patrick talking to in the videos and does that person know anything about what happened to her?