BOSTON POLICE CHIEF: 'We Will Turn Over Every Rock' To Find Those Responsible For Marathon Explosions

Courtesy of CNNFBI agents will take the lead in the investigation into the explosions at the Boston Marathon Monday, officials said at a press conference tonight.

"We will turn over every rock to find who is responsible for this," said Boston Police Commissioner Ed Davis.

Davis confirmed that at least three people died and 130 were injured in the incident. CNN and NBC have reported that those who died was an 8-year-old child.

Davis also debunked reports that claimed the Boston Police Department was a holding a suspect at Brigham and Women's Hospital.

He would not say whether all authorities had found all of the explosive devices yet.

"No further devices have been located at this point in time," Davis said, adding, "I am not prepared to say that we are at ease at this time."

Massachusetts Governor Deval Patrick said that Boston will remain in a state of heightened security as the investigation continues.

"The city of Boston...will be open tomorrow, but it will not be business as usual," Patrick said. "Expect random checks of bags, heightened law enforcement."

At a press conference this evening, President Barack Obama said that it was not clear who was behind the explosions, but that those responsible would "feel the full weight of justice." The White House confirmed later that the administration is considering the incident "an act of terror."

At Monday night's press conference, FBI investigator Richard DesLauriers said that "it is a criminal investigation that is a potential terrorist investigation."

The next press conference will be at 9:30 a.m. Tuesday.