Updated

A $10,000 reward has been offered for information leading to the safe return of 18-year-old Kelsey Smith, who was forced into her car at a Target store on Saturday.

"Every indication is, it’s been an abduction," Overland Park Police Chief John Douglas told FOX News on Tuesday. "So far, our best information is coming from the surveillance video."

Police viewed the footage Monday. The video shows Smith, of Overland Park, Kan., leaving the store around 7:10 p.m. She had put packages into her car when someone ran toward her, police said.

"As she opened the driver's side door, the individual sprinted up behind her and pushed her into the car," said Overland Park Police Capt. Tom Fredrickson.

Click here to watch the surveillance video from MyFOX4 in Kansas City.

Douglas said Tuesday that authorities are enhancing the footage to get a closer look at what transpired just before Smith disappeared. Police were searching for a man caught on surveillance video leaving the store in hopes of getting information on what he may have seen. The man is being called a "person of interest."

Police searched throughout Monday night for any signs of the teenager, and the hunt continued Tuesday. Around 200 people passed out fliers and helped canvas the 5-square-mile area around where she was last seen on Monday. The family has also launched a Web site, www.findkelsey.com. Police are planning a news conference for 5 p.m. Tuesday.

Click here to see pictures from the site.

Smith's oldest sister, Stevie, told FOX News that all of the missing teen's family and friends gave DNA samples to police. Authorities also took fingerprints of everyone who has been in Smith's car in the past 10 days.

Police want to know where Smith was in the two-hour span between leaving Target and the discovery of her car across the street at Macy's.

Investigators said they don't know if Smith was picked at random or abducted by someone she knew. Monday night, they released information about a "person of interest" who entered the store after Smith and left before she did.

Detective Bob Miller said two callers who have phoned police since the video's release both alluded to one individual.

"He walked in shortly after her and left shortly before her, and is obviously parked out somewhere by her," Miller said. "We're confident we're going to get this guy identified today."

"There were other people in the store at the same time Kelsey was, but this guy seemed to stand out," Fredrickson added. "We're not calling him a suspect. He's an individual who may have information that is helpful to us. We want to find out his name and speak to him."

Surveillance video of this individual shows a male in his 20s, with closely cropped dark hair and facial hair on his chin. He was wearing black shorts, a white T-shirt, black Converse sneakers and what appeared to be a long, gold necklace. The man who rushed toward Smith in the surveillance video is wearing similar clothing.

"The biggest piece of information we have that’s caused the most excitement we have is this person of interest," Smith's father, Greg, told FOX News on Tuesday. "Somebody out there knows this person or saw this person and all they have to do is call the police and tell them who he is."

Police are trying to determine whether the man rushing toward Smith at the car is the same person captured on video coming out of the store earlier.

"I can’t say with any certainty it’s the same person we want to talk to," Douglas said, but added that the man who rushed toward Smith at the car is wearing a white shirt with shorts.

He said calls came pouring in after the video stills were released Monday night with potential leads on who the man may be.

"I can’t say we’ve settled on any one yet but it’s been very good — we’ve had a lot of leads from this," Douglas said.

Searchers on Tuesday were focusing on apartment buildings around the Target. Since the man in the surveillance video appears to be in his 20s, he likely does not live at home with his parents and probably rents a nearby apartment, police think. All volunteers groups consist of one female and two males, since police are concerned about the safety of females out by themselves.

Smith, who graduated from high school less than two weeks ago, had been expected home by 7:30 p.m. Saturday. She spoke to her mom from inside the Target at 6:57 p.m. She and her boyfriend, who was at her house waiting for her when she didn't show up, had planned to attend a pool party and then go to dinner to celebrate their six-month anniversary. Smith’s sister told FOX News that her boyfriend planned on giving a promise ring to her.

About two hours after Smith disappeared, her grandparents found her gray 1987 Buick in a parking lot at a nearby mall with her purse and packages still inside. Her ATM card and cell phone were both missing from her purse, but neither have been used since Saturday.

Smith’s parents said their children always called them whenever they were going to be getting home later than expected, or if they change their plans. And because they never received such a phone call from Kelsey, they believe someone abducted her.

"There’s a rule in our house — our children knew if you change location, you call your parents. They always, always let us know," said her mother, Melissa Smith. "She’s very responsible."

Greg Smith has been in law enforcement for 16 years. He described his daughter as an outgoing young woman who plans to be a veterinarian. She also worked at a local AMC movie theater.

"From a cop standpoint, I understand everything that's going on," he said. "I know what some of the key things are, what the key time frames are. I try not to think about that."

Meanwhile, Miller said the Smith family was bearing up "as well as can be expected."

"I talked to the dad early this morning. They're starting to crumble a little bit because we're past the 48-hour window," Miller said. "He knows the urgency and the gravity of the situation now."

Family and friends also said Smith is a fighter, and anyone who may have abducted her likely is having a hard time keeping her subdued. They also described her as very well liked who was in a good relationship with her boyfriend.

"She’s just one of those kids, she steps in a room and it lights up," Greg Smith said.

Smith is about 5-foot-6-inches tall, weighs about 120 pounds and has long brown hair and brown eyes. She was last seen wearing a pink tank top, black cotton shorts and tennis shoes.

Anyone with any information that may help the investigation is encouraged to call the TIPS hotline at 816-474-8477 or the Overland Park Police at 913-895-6300.

FOX News' Alicia Acuna and The Associated Press contributed to this report.