Grimm's staff discovered the damage Sunday morning. Chunks of cement and several smaller rocks were used to break three window panes. Grimm and his campaign later told media outlets that computers inside the office had their hard drives erased.
"This is a disgraceful act of cowardice that is beneath the people I represent," Grimm said in a statement obtained by Politicker. "Here in Staten Island, we are a family community, which is why despite our differences in opinions and political views, we have never seen an attack on a campaign escalate to this level. In 2010, campaigns across the nation were fueled with high levels of passion, yet even then we never saw anything as dirty or disgraceful as this. Even though this is not an official office, this heinous act represents an assault on democracy and the political process, more so than it does on me as person or a candidate. I do believe this is a politically motivated crime, and will continue to work closely with the NYPD in identifying and prosecuting those responsible."
A New York Police Department spokesman told Politicker the incident "is being investigated as a criminal mischief."
"NYPD computer crimes will investigate further any assertions that computers there were tampered with," NYPD Deputy Commissioner of Public Information Paul Browne said.
In an interview with The Staten Island Advance on Sunday night, Grimm said that the Linux operating system had been installed on the office's computers, which contained "[a]ll of my polling data, all of the data from my IDs of voters, and a bunch of other campaign information."
"But fortunately we had everything backed up from literally hours before, so we don't lose anything because we have backups," Grimm said.
Grimm told the newspaper he thought the vandalism was staged to cover for the computer tampering.
According to the congressman, the office has not had its locks changed since the time when it was a car dealership, meaning that "hundreds" of people could have keys to the space.
Capitol Police have also been notified about the incident.
"You know, especially in light of what happened with Gabby Giffords, we're not in the world today where we can shrug things off," Grimm said. "Violence is violence. Throwing large stones and concrete through the window is an act of violence, and we've got to take it seriously."
Grimm's 2010 campaign has received attention from federal investigators. Several people who worked on the campaign have been questioned by the FBI in the past year, and agents were apparently also looking into Grimm's failure to file paperwork related to a trip to Cyprus last year.