CHARLOTTESVILLE, Va. — Several surveillance videos show her walking and running alone. But police say new footage of a missing University of Virginia student appears to show someone following her the night she disappeared. And that same person told police that he saw another man put his arm around Hannah Graham.

Business surveillance cameras along the Downtown Mall in Charlottesville, Va., captured video of a man following Graham early Saturday, Charlottesville Police spokesman Lt. Ronnie Roberts told CNN.

A man later came to the police department and told officers he was following the 18-year-old sophomore because she looked distressed, authorities said.

Police have been searching for Graham since Sunday.

At a Wednesday press conference police said they had received more than 100 tips, interviewed more than 50 people and had new video to examine.

Detectives visited businesses on the Downtown Mall, a pedestrian area located just over a mile away from the UVa. campus, to see if anyone had surveillance video that might show Graham’s path the night she disappeared.

Wednesday evening Capt. Gary Pleasants told CBS 6 that they examined two new videos, which showed an unidentified white male following Graham.

The first video was taken at 1:06 a.m.  from Sal’s Pizza, located at 221 E. Main St. It shows a white male walking into the cameras view, he looks over his shoulder, then steps into a doorway and Graham walks past him, police said.

After she passes, the male starts walking behind her. The second video picks up at 1:08 a.m., from a camera at Tuel’s Jewelers located at 319 E. Main St. The video shows Graham walking with the same white male some distance behind her, Pleasants said.

Pleasants then said that the man in the video came to the police station, and said he had also left his story on the tip line.

He told police that he was walking with her to make sure she was okay, because she seemed physically distressed and he “wanted to make sure she got safely wherever she was going.”

The man told police that he saw a black man approach Hannah, and that man put his arm around her. The unidentified man told police she didn’t react, and seemed to know him. Once those two started speaking, he said it appeared the black male was “was either known to Ms. Graham or was trying to help her.”

So he went on his way, he told police. He said the two were standing there talking when he left.

Graham’s parents say they’re worried something happened to her after she left a gathering with friends Friday night in Charlottesville.

“Hannah is beyond precious to us,” John and Susan Graham said in a statement released by police Wednesday. “We are truly devastated by her disappearance. It’s totally out of character for us not to have heard from her, and we fear foul play.”

The teen’s mysterious disappearance comes nearly five years after the unsolved killing of another student in the area, sparking fears from some that there could be a connection.

Morgan Harrington, a 20-year-old Virginia Tech student, went missing after attending a Metallica concert in Charlottesville in October 2009. Her remains were found on a farm months later. Police have yet to track down her killer, and her family has long said they suspected there could be other victims.

Could there be a link to the Harrington case?

“Certainly the question has arisen. It’s certainly a legitimate question,” Charlottesville Police Chief Timothy Longo told reporters Wednesday.

“If there comes a time where we believe there is a substantive link to those two investigations, we’ll share that with you,” he said.

So far, the police chief said, investigators haven’t found anything to tie the two cases. And they haven’t found any sign of foul play, despite the concerns the teen’s parents have expressed.

“As a parent, I’d be very concerned, but we don’t have any substantive evidence to confirm that,” he said. “But you know, they’re speaking from their heart.”

Surveillance videos offer clues

Police describe Graham, a sophomore, as a straight-A student, an accomplished athlete and a good friend.

She’s about 5-foot-11 with blue eyes, light brown hair and freckles, the university said in a release asking for tips about the teen’s disappearance.

She left a dinner with a group of friends around 11 p.m. Friday. About 1:20 a.m. Saturday, she sent a text to friends saying she was lost, CNN affiliate WTVR reported.

Police believe she may have been under the influence of alcohol, Longo said, and may have been vulnerable or unable to defend herself.

Investigators have tracked down several surveillance videos that show her that night outside a pub, near a gas station and in a downtown shopping mall, Longo said. But it’s not clear where she’s going or whether she’s in trouble.

One video shows her running along the road near a Shell station.

That initially concerned investigators, Longo told reporters.

But in later videos, he said “it does not appear at least at that point that she’s being pursued.”

Investigators are looking for more surveillance videos that they believe could show Graham in downtown Charlottesville.

And the search is far from over. As time passes, investigators say their search area grows. Search teams from the Virginia Department of Emergency Management are helping, CNN affiliate WVIR reported.

“This investigation has been aggressive and will continue to be aggressive,” Longo said.

CNN affiliate: Corridor has ‘infamous reputation’

Gil Harrington told CNN affiliate WTVR that it’s too soon to draw a direct connection between her daughter’s death and Graham’s disappearance.

“Your mind goes there, but I think that’s premature in a way,” she told WTVR. “We have the possibility of having a good outcome with Hannah. We need to keep that in mind.”

Right now, Gil Harrington has a poster with pictures of the University of Virginia student on her fridge, beneath the word “MISSING.”

Through “Help Save the Next Girl,” an organization founded after her daughter’s disappearance and death, she’s pushing residents of Charlottesville to call in tips.

On Wednesday, the organization tweeted that the Harringtons had left a message in large letters taped on Charlottesville bridge spelled out their support of the search: “PLEASE FIND HANNAH.”

“Your mind just sickens,” Gil Harrington told CNN affiliate WVIR. “You think, how can it be, another girl taken.”

This isn’t the first time a woman has gone missing in the area. The disappearances of Harrington and Graham, along with several other past cases in the area known as the Route 29 corridor has given the area an “infamous reputation,” WTVR says.

“I don’t know. Either there is a commonality or a crime spree,” Harrington told WTVR. “We have long passed a critical mass that needs looking at. If you look at the map of missing and abducted along Route 29 — it’s not a normal pattern.”

Source: CNN/WTVR