Boston Mayor Tom Menino speaks from his wheelchair during a news conference, as Massachusetts Gov. Deval Patrick and public safety officials watch, in Watertown, Mass., on Friday, April 19, 2013. (Reuters)

Boston Mayor Thomas Menino (D) said Sunday that the information he has about the Boston Marathon bombings suggests the two individuals suspected of carrying out the attack acted alone.

"All of the information that I have they acted alone, these two individuals, the brothers," Menino said on ABC News's "This Week With George Stephanopoulos."

Only one of the two men suspected of the bombings is still alive. The man, Dzhokhar Tsarnaev, was taken into custody Friday and has been hospitalized with gunshot wounds. "He is in serious but stable condition and we have not been able to interrogate him at this point in time," Boston Police Commissioner Ed Davis said on CBS News's "Face The Nation." "There’s a special FBI interview team that’s coming out to talk to him, but at this point in time we have not done that."

Tamerlan Tsarnaev, the second suspect and older brother of Dzhokhar Tsarnaev, was killed in a shootout with police last week.

The motivation behind the bombings is not clear, Massachusetts Gov. Deval Patrick (D) said.

"It's hard for me and for many of us to imagine what could motivate people to harm innocent men, women and children in the way that these two fellows did," Patrick said on "Face The Nation."

Davis said that there is reason to believe the suspected bomber had been planning other attacks. He said evidence suggests the two suspects "were going to attack other individuals. That’s my belief at this point."

Menino offered a different view, saying: "I'm not convinced at all that they were planning more attacks."