Reports said investigators had begun questioning Tsarnaev, who was communicating on paper because he is still unable to speak.
Davis said he could not “dispute” reports that Tsarnaev was communicating with law enforcement officials.
“There’ve been widely published reports,” Davis said. “I don’t dispute that, but I don’t have any information on that myself.”
Tsarnaev, age 19, and his older brother Tamerlan Tsarnaev, 26, who died in a gunfight with police on Friday, are suspects in last week’s bombing, which killed three and left dozens injured. Dzhokhar Tsarnaev was captured late Friday after a daylong manhunt in which authorities shut down Boston and some surrounding areas to do a door-to-door canvass of the area.
Tsarnaev has not yet been read his Miranda rights, allowing authorities to question him without a lawyer under the public safety exception.
“The decision not to read him the Miranda rights was made by federal officials,” Davis said. “This is a unique clause to the terrorism clause that we’ve not dealt with at the local level before. So we are standing by and watching that at this point and time to see how that develops, and the lawyers are involved in that decision, but we’re anxious to talk to him and the investigators will be doing that as soon as possible.”
Davis said he was confident the brothers were planning more attacks.
“The two suspects were armed with hand guns at the scene of the shooting and there were multiple explosive devices, including a large one that was similar to the pressure cooker device that was found on Boylston Street,” he said. “I saw that with my own eyes. I believe that the only reason that someone would have those in their possession was to further attack people and to cause more death and destruction.”
Davis said an officer who was critically wounded in the shootout with the brothers, and who lost nearly all of his blood, was doing “much better” and able to communicate with his family using hand signals.
He added that Boylston Street, a complicated crime scene where the bombs exploded, could potentially reopen to the public in the next 24 to 48 hours.