Boston Marathon Bombers 'Caught on Camera'
Officials take crime scene photos two days after two explosions hit the Boston Marathon in Boston, Massachusetts. The investigation of the Boston Marathon bombing is focusing on a suspect or suspects believed to have carried heavy bags or backpacks, but entered a third day on Wednesday without any arrests or word on who was responsible.Reuters

The teen suspect in the Boston Marathon bombings, who sustained grievous injuries to his throat following an intense gunfight, has started communicating to officials through written notes, reported ABC and NBC news networks.

Dzhokar Tsarnaev, 19, was admitted to Boston's Beth Israel Deaconess Medical Center where he was said to be in a serious but stable condition after being taken into custody by federal agents on Friday night.

On Sunday, authorities told reporters that the suspect's throat was injured and as a result was unable to talk. However, by evening Dzhokar gained consciousness and started communicating in writing. The investigating officials are desperately seeking his statement on the motives behind the attack and whether he and his brother, Tamerlan Tsarnaev, who died on Thursday night following a shootout with police, had any other accomplices.

Meanwhile, US attorney and Federal prosecutor Carmen Ortiz was reportedly preparing criminal charges to be filed against Dzhokar who remains in the Intensive Care Unit (ICU) of the medical centre for the second day. No official announcement has been made on the same.

The two brothers - Dzhokar Tsarnaev and Tamerlan Tsarnaev - who had moved to the United States in the 2000s from the central Asian country of Kyrgyzstan along with their parents, were narrowed down as suspects in the Boston Marathon bombing after surveillance camera footage showed them carrying suspicious-looking backpacks near the location. The devastating incident killed three people and left over 170 injured on 15 April.

Soon after officials released their images on Thursday, the duo shot dead a guard at the Massachusetts Institute of Technology campus and fled the spot in a vehicle. Police chased the vehicle resulting in a wild gunfight that left Tamerlan brutally wounded. Dzhokar in a hurry to escape from being apprehended by the officials got into the vehicle and sped from the location running over his brother who was reported to be alive. Tamerlan was rushed to Beth Israel Deaconess Medical Center where he was declared dead.

On Friday, officials captured Dzhokar from a boat near Watertown ending a day long manhunt. It was reported that the suspect attempted suicide by pulling off the trigger in his mouth.

Officials investigating the case have reported that they will scrutinise Tamerlan's visit to Russia in 2012 to see whether he was influenced by Chechen separatists or the Islamist struggle against the West. They will also investigate into the brothers' knowledge about developing explosives.

Cambridge Police Commissioner Robert Haas told the Associated Press that it was unclear if the brothers applied for a gun permit.

According to various reports, the bombings have not been linked to any overseas terrorist network or any larger terrorist cell within the US. Islamist separatist groups on Sunday denied their involvement in the crime stating, "We are at war with Russia, which is not only responsible for the occupation of the Caucasus, but also for heinous crimes against Muslims."

Boston Police Commissioner Ed Davis said the brothers may have been planning future attacks considering the weapons and unexploded bombs they were carrying.