MADISON, Wis. -- Police in Madison, Wisc., now say a missing student found alive Wednesday was abducted at knifepoint from her apartment near the University of Wisconsin Saturday morning.

AUDREY SEILER Charge Her? Pictures From Search Scene VIDEO Police Briefings: First | Second Security Tape RESOURCES/TIPS Find Audrey Web Site Anyone with information can contact the Madison Area Crime Stoppers at (608) 266-6014.

University of Wisconsin student Audrey Seiler was found four days after she vanished from her off-campus apartment without a coat, purse or cell phone, Madison police say.

An officer said 20-year-old Seiler, of Rockford, Minn., was transported to an area hospital by ambulance and reunited with her family. Police said she sustained non-life threatening injuries.

The doctor who treated Seiler said she was cold and dehydrated. Dr. Philip Schultz said during a late-afternoon news conference that she also had muscle aches from being confined.

Officers converged on the area Wednesday afternoon after a citizen spotted someone in the marsh and called police just before 1 p.m. CST, said Noble Wray, assistant chief of Madison police, at the news conference. Wray said police have secured a perimeter in a marshy area about two miles from campus where Seiler was found and where they believe the suspect still is.

Police say Seiler didn't know the man who abducted her. She believes he may have also had a gun, but she never saw it.

One officer says, "She was not free to leave."

Wray described the suspect as a white male in his late 20s or early 30s, about 6 feet tall, last seen wearing a black sweatshirt, jeans and black hat and armed with a gun and a knife. Wray classified the case as a "missing persons investigation," declining to say whether there was an abduction or any other crime committed.

Seiler's parents spoke briefly at the news conference and gave few details about the reunion.

"Audrey was overjoyed to be back with us ... and a bit surprised at all the hullaballoo," said Keith Seiler, Audrey's father.

Meanwhile, police and dogs are searching the secured area. Madison police do not have their own helicopter, so they are putting a thermal imaging camera on a Milwaukee TV station's chopper in their search for the suspect.

Assistant Madison Fire Chief Carl Saxe said the special cameras will pick up images of anything that is 98 degrees or higher and help police find the suspect.

"On a cool day like today, it will be easy to pick out anyone hiding in the brush or grass," Saxe said.

Saxe said it's important for people to stay away from the search area.

Woman Had Last Been Seen On Surveillance Tape

Surveillance tape from the Saturday Seiler disappeared showed her peering outside as if she were waiting for someone or something, WISC-TV in Madison reported.

Seiler's roommate last saw her leaving their apartment about 2:30 a.m. CST Saturday. Madison police started looking for her around 2 p.m. Saturday. Officers and search-and-rescue dogs searched the area Sunday, and the FBI joined the search Monday.

Hundreds of friends and family, including her brother Kyle, classmates, teachers and many others from the Rockford area, have been in Madison for the search. They combed the campus area for clues Tuesday, including the woods and high grass of the University of Wisconsin Arboretum for any sign of the missing woman.

Madison police said early Wednesday there was little reason for increased hope. They said they had gotten hundreds of tips, but none were panning out.

Seiler Attacked In February

The area around Seiler's apartment is not known to be particularly dangerous; however, she was attacked by an apparent stranger Feb. 1, WISC reported.

Detectives are refusing to release specifics of the report, but police told the television station that Seiler was attacked one block from her home.

Police said they don't know if the attack is related to her disappearance. She was approached from behind, struck unconscious and left in a secluded area. Because she was attacked from behind, police do not have a description of the attacker in that case.

"(The attacker) left her unconscious and moved to another location outside, and eventually she was found and she was treated for those injuries," said Madison officer Larry Kamholz.

Her family revealed Tuesday that Audrey considered that a random act. Police said they have no link between that attack and her disappearance.

Seiler's story hit national newscasts Tuesday, with some drawing parallels to the case of Dru Sjodin, the University of North Dakota student who was last seen Nov. 22, 2003, leaving a shopping mall in Grand Forks, N.D. A convicted rapist was ordered earlier this month to stand trial on charges he kidnapped her. Investigators have said they believe Sjodin is dead.