Also, the killer may have lied about his or her whereabouts from 1 to 3 a.m. Saturday, when Thomas and Lisa Haines and their teenage son Kevin were slain, Manheim Township police said.

"If you know this person, you may not think they are capable of this type of crime," police said in a news release. "They may also have fabricated an alibi concerning their whereabouts during this time frame. They may not have a prior record of violence."

Chief Neil J. Harkins said investigators are working on tips that have come in during the past few days.

He previously said there were no suspects, but on Wednesday was less specific.

"The best I can tell you right now, the fair thing to say is we're still working on leads, promising leads," he said.

The Haineses' daughter, Maggie, went to her parents' bedroom after being awakened by noise around 2 a.m. Saturday, police said. Her father was lying on the bed and her mother was sitting on it.

Lisa Haines told her daughter, who had returned home from Bucknell University for the summer a day earlier, to seek help. She summoned police from a home across the street.

The couple and Kevin, a 16-year-old high school sophomore, were found dead inside the home. A back door was ajar and nothing appeared to have been taken.

Detectives spent some time on Wednesday looking into a burglary that occurred overnight at a home north of Lititz, about seven miles from the scene of the killings. They concluded the two incidents were unrelated.

SUSQUEHANNA
Bridge delay
HARRISBURG -- Rain and wind kept crews from performing last-minute work on the westbound span of the Pennsylvania Turnpike's new Susquehanna River bridge, delaying its opening until this evening at the earliest.

A ribbon cutting took place on the $84 million bridge yesterday, but workers were unable to paint lines, remove concrete barriers and perform other final tasks.

The 1.1-mile bridge connects Fairview Township in northern York County with Steelton in Dauphin County.

On the Web:

Bridge project: http://kci.com/projects/srb/
RESEARCH ON MICE
Hair regeneration
PHILADELPHIA -- Researchers at the University of Pennsylvania School of Medicine have found that hair follicles in adult mice regenerate by reawakening genes once active only in developing embryos.

The findings, revealed yesterday and published in the May 17 issue of the journal Nature, provide unequivocal evidence for the first time that like other animals such as newts and salamanders, mammals have the power to regenerate, researchers said.

A better understanding of this process could lead to novel treatments for hair loss, other skin and hair disorders, and wounds.

"We showed that wound healing triggered an embryonic state in the skin that made it receptive to receiving instructions from wnt proteins," said senior author Dr. George Cotsarelis, associate professor of dermatology. "The wnts are a network of proteins implicated in hair-follicle development."

Researchers previously believed that adult mammal skin could not regenerate hair follicles.

In fact, investigators generally believe that mammals have essentially no true regenerative qualities. (The liver can regenerate large portions, but some of the original liver has to remain so that it can regenerate.)

In this study, researchers found that wound healing in a mouse model created an "embryonic window" of opportunity. Dormant embryonic molecular pathways were awakened, sending stem cells to the area of injury. Unexpectedly, the regenerated hair follicles originated from non-hair-follicle stem cells.

"We've found that we can influence wound healing with wnts or other proteins that allow the skin to heal in a way that has less scarring and includes all the normal structures of the skin, such as hair follicles and oil glands, rather than just a scar," explains Cotsarelis.

By introducing more wnt proteins to the wound, the researchers found that they could take advantage of the embryonic genes to promote hair-follicle growth, thus making skin regenerate instead of just repair. Conversely by blocking wnt proteins, they also found that they could stop the production of hair follicles in healed skin.

Increased wnt signaling doubled the number of new hair follicles. This suggests that the embryonic window created by the wound-healing process can be used to manipulate hair-follicle regeneration, leading to novel ways to treat hair loss and hair overgrowth.

These findings go beyond just a possible treatment for male-pattern baldness. If researchers can effectively control hair growth, then they could potentially find cures for people with hair and scalp disorders, such as scarring alopecia where the skin scars, and hair overgrowth.

This research was funded in part by the National Institute of Arthritis, Musculoskelatal and Skin Disease and the Pennsylvania Department of Health. Other co-authors in addition to Cotsarelis are Mayumi Ito, Zaixin Yang, Thomas Andl, Chunhua Cui, Noori Kim, and Sarah E. Millar, all from Penn.

Cotsarelis and Ito are listed as inventors on a patent application related to hair-follicle neogenesis and owned by the University of Pennsylvania. Cotsarelis also serves on the scientific advisory board and has equity in Follica, a start-up company that has licensed the patent from the University of Pennsylvania. Cotsarelis was also a co-founder of Follica.