(CNN) - President Barack Obama said at the conclusion of the Boston Marathon bombing manhunt on Friday night that "we've closed an important chapter in this tragedy," adding that those who carried out the "vicious attack" failed because Americans "refuse to be terrorized."
Speaking at the White House, Obama praised the work of law enforcement after they captured the second of two suspects following a daylong search, and pledged continued federal law enforcement, homeland security and intelligence resources to the ongoing investigation.
Obama maintained "whatever hateful agenda" may have been behind the attack that killed three people and injured 180 others on Monday in two blasts near the finish line of the storied road race "will not and cannot prevail."
The president said there remained many unanswered questions and cautioned against jumping to conclusions as the investigation continues.
He urged people not to "rush to judgment" about motivations or entire groups.
Obama expressed gratitude for local, state and federal law enforcement efforts and praised the city and the nation in the face of an attack being investigated as a terrorist act. He noted that it did not ultimately succeed.
"They failed because the people of Boston refused to be intimidated," Obama said. "They failed because as Americans, we refuse to be terrorized."
An Obama administration official said the president heard that suspect Dzhokar Tsarnaev, 19, had been taken into custody just outside Boston in Watertown from staff and media reports. FBI Director Mueller called him to brief on details, the official said.
The other suspect, a man identified as his brother, Tamerlan Tsarnaev, 26, died early on Friday following a shootout with police, officials said.
- CNN's Jessica Yellin contributed to this report.