Washington ( CNN ) -- When President Barack Obama addressed the nation in the hours following Monday 's Boston Marathon bombing , he did not use the word `` terror , '' immediately raising questions . When he took the podium at the White House less than 24 hours later , his phrasing changed . But he still was very careful about what he said , making separate points . `` Any time bombs are used to target civilians , it is an act of terrorism , '' Obama said . He said it was unclear who carried out the attack and why , but that the Boston bombings were a `` heinous and cowardly act '' that the FBI is investigating as an act of terrorism . The two bomb blasts near the downtown finish line of the storied marathon killed three people , including an 8-year-old boy , and sent more than 170 others to local hospitals , some with critical injuries . With developments unfolding late on Monday , Obama spoke to the nation from the White House , saying `` we still do not know who did this or why '' and cautioning Americans against jumping to any conclusions . `` But make no mistake , we will get to the bottom of this and we will find out who did this . We 'll find out why they did this , '' he said . Obama , calling attack 'terror , ' shifts to response . Though Obama did n't mention `` terror , '' federal investigators and a White House official later classified the bombings as such . Those close to the case have said it is not clear whether the attack was domestic or foreign in origin . It makes sense Obama would be cautious in his initial public remarks and then clarify matters later with more information known , said Aitan Goelman , a former assistant U.S. attorney who helped prosecute the Oklahoma City bombing case . `` The president is absolutely right in cautioning people we do n't know who did this , '' Goelman said . 'Boston will overcome , ' mayor vows amid bombing investigation . Careful decision-making in communicating information to the public seems to reflect lessons learned by a chief executive who has had to navigate the aftermath of attacks or threatened attacks where American lives were lost or threatened . `` There were three attacks in the first 17 months of the administration , four if you count Fort Hood , '' said Matthew Miller , who served as a director of the Office of Public Affairs for the Justice Department during Obama 's first term . `` What we learned in dealing with each of those is it 's important for government officials to communicate early and reassure the public , '' he said . The president learned that lesson on Christmas Day in 2009 when a passenger attempted to detonate a bomb hidden in his underwear aboard an international flight heading into Detroit . The White House called it an attempted terrorist attack and it took Obama three days to address the incident publicly , delay that some Republicans in Congress criticized . A thwarted attempt to detonate explosives in New York 's subway system in September 2009 , the November 2009 shooting massacre at Fort Hood , Texas , and a failed bombing of New York 's Times Square in May 2010 offered valuable lessons on communicating early , often and cautiously , Miller said . The administration has also benefited from consistency in staffing . Key officials , including White House chief of staff Denis McDonough , who in 2009 served as National Security Council chief of staff , and homeland security adviser Lisa Monaco , who formerly served as a senior Justice Department official , are at Obama 's side now . The administration also learned a tough political lesson around the word terror when Obama was hesitant to say it outright when first describing the deadly attack on the U.S. diplomatic mission in Benghazi , Libya , last September . Details emerge : Boston bombs may have involved pressure cooker , timer . The president did call the attack one of several `` acts of terror . '' The administration 's reluctance to clearly label that attack terrorism and comments blaming events initially on a response to an anti-Islamic film ignited partisan bickering and an election-year showdown with Republicans over his administration 's handling of the matter . Politics aside , experts point out that classifying an attack as terrorism carries important legal and investigative meaning . `` You know , there 's been much discussing about the parsing of words : is this terrorism , is n't it terrorism , it 's criminal ? First of all , terrorism is a crime . So it 's automatically a criminal case if it 's a terrorism case , '' said Tom Fuentes , a former FBI assistant director and CNN contributor . `` But secondly , if it was not terrorism , the FBI would not be in charge . It would be Boston P.D . running this case . So it 's clear the authorities are absolutely clear . This is a terrorism investigation . It 's a terrorism case , '' he said .
President Barack Obama uses ' ` ` ' '' in latest comments on the bombings . The lack of the word ` ` terror '' in Obama 's comments on Monday raised questions . Obama learned very early on about the political ramifications of using the word ` ` terror ''