As U.S. President Barack Obama set a January deadline for proposals to deal with gun violence, new details emerged Wednesday about the mother of the gunman who killed 27 people in a Connecticut shooting rampage last week.

A day before her son killed her, Nancy Lanza was on vacation alone at a luxury resort in New Hampshire, friends said Wednesday.

Lanza checked in to the Omni Mount Washington Resort & Hotel in Bretton Woods last Tuesday and checked out Thursday afternoon, the hotel said. Less than a day later, authorities say, her son Adam Lanza killed her and then opened fire in Sandy Hook Elementary School, killing 20 children and six adults there.

Road trips alone were not uncommon for Nancy Lanza, according to her friends, who said she seemed to be in good spirits during the trip and felt comfortable leaving her 20-year-old son unsupervised in recent years.

Authorities have said the shooter took three of his mother's weapons -- two handguns and a Bushmaster AR-15 rifle -- to the elementary school Friday.

His deadly shooting rampage has ignited renewed national debates over gun control, mental health care and school safety.

Speaking five days after the massacre, Obama said Wednesday that a new group led by Vice President Joe Biden is charged with developing "concrete proposals" for dealing with gun violence "no later than January." The group will include some Cabinet members and outside organizations.

"This is not some Washington commission. This is not something where folks are going to be studying the issue for six months and publishing a report that gets read and then pushed aside," Obama said. "This is a team that has a very specific task to pull together real reforms right now."

While politicians continued to call for action, singer Paul Simon offered a tribute to a beloved Sandy Hook teacher who died trying to save her students. A statement from Simon's publicist said teacher Victoria "Vicki" Soto's parents were family friends.

At their request, on Wednesday he sang "The Sound of Silence" at her funeral.