When Paul and Monica Shay were gunned down July 2 in their country home in Montgomery County, Pa., it quickly became clear to those who knew the couple that their loss would be felt especially deep in the East Village.

What longtime friends remember most about the Shays — who lived on East 10th Street — is their roles as leaders in the fight for housing, which in the 1980’s and 90’s included frequent clashes with the police during demonstrations for the rights of squatters in and around Tompkins Square Park.

“There’s a short list of people who when they say, ‘let’s do something,’ they mean they’re going to do it,” said Seth Tobocman, an activist artist and friend of the Shays.

“Kathryn and Paul were always on that list,” he continued, referring to Ms. Shay by her nickname.

Since the shooting, crowds of friends and neighbors have twice gathered publicly to remember the Shays, most recently July 9 in Tompkins Square Park.

Ms. Shay died July 7, while Mr. Shay remains hospitalized and in critical condition. Three other victims include Mr. Shay’s nephew Joseph Shay, the younger Mr. Shay’s girlfriend Kathryn Erdmann, and her 2-year-old son Gregory Erdmann. Ms. Erdmann and the elder Mr. Shay are the lone survivors.

John Penley Homeless activists in Tompkins Square Park, 1989.

The community remembered Ms. Shay as not only a professor at Pratt Institute, but also as a member of organizations like the October 22nd Coalition, a group that campaigns against police brutality, and ArtTable, a leadership organization of professional women in the visual arts.

Mr. Shay, who owned a small plumbing business, is remembered for the work he did with helping squatters install toilets and running water in abandoned buildings, said Clayton Patterson, an artist who lives on the Lower East Side.

“They were front-line people,” said Mr. Patterson, who gained notoriety in 1988 for his documentation of the Tompkins Square police riot.

The grief felt by many in the neighborhood was exacerbated last week when the authorities in Pennsylvania announced that the suspect, Mark Richard Geisenheyner, indicated that he shot the couple because he felt he was cheated out of the spoils of an insurance fraud scheme involving the elder Mr. Shay.

“Life is such that there are surprises,” said Mr. Patterson. “But that would be certainly a big surprise to me.”

Pennsylvania officials are continuing to investigate the claims of Mr. Geisenheyner. Andrew Erba, an attorney for Mr. Shay, said he has not received any calls from investigators.

Even as friends express their disbelief that the Shays could have been involved in the scheme, friends of the couple say that the allegation should not diminish the work that they did for the squatter movement — nor does it lessen the grief that many here feel.