A suspect in the Boston bombings has been caught on CCTV apparently planting the second of the two explosives in what investigators have hailed as a major breakthrough in the case. Video obtained by the FBI shows the suspect placing a bag near the Lord and Taylor department store while talking on a cellphone moments before the twin blasts ripped though the city centre, killing three and injuring more than 180. The unidentified man is also captured using his phone at the moment the first explosion detonated 100 yards away on Boylston Street on Monday and 12 seconds before the second blast close to where he is standing.