>>> turning now to boston and the latest on the investigation into the marathon bombings. there is new information on exactly how the bombs were made and a gripping new account of the night it all ended from the man who was carjacked by these two accused bombers. also a big piece of evidence was moved today. our nbc news national investigative correspondent michael isikoff reports.  >> reporter: dzhokhar tsarnaev is now held at a special medical prison outside boston . u.s. marshalls moved him overnight after a week at beth israel hospital . tsarnaev, badge ebandaged and unable to speak, but the judge ruled he was alert. when told he could face the death penalty he showed no emotion, a source tells nbc news. today federal agents searched this landfill looking for his laptop and fireworks receipts and the boat where with he was the night of his capture was hauled away. a government analysis provides new details about the bombs. the designs followed one outlined in "inspire" magazine published by an al qaeda affiliate using low explosives consistent with with commercial fireworks, adding shrapnel and triggering by a toy car radio controller. but some elements go beyond the inspire blueprint.  >> this design indicates a level of sophistication and determination to really make these bombs reliable.  >> reporter: also today a gripping account from the driver of the suv carjacked by tsarnaev and his brother. danny , a 26-year-old chinese native, was taken on a wild 90-minute ride before escaping and alerting police. during the ride the elder brother tamerlan made a startling confession.  >> i killed a cop if cambridge.  >> reporter: danny spent hours talking to the fbi and shared his story with with james allen fox. fox said danny was scared for his life but made small talk and played up his foreign heritage.  >> he was only trying to save himself. but through that process it looks like he may have saved countless others.  >> reporter: when the tsarnaevs stopped for gas danny bolted and called the police who tracked his stolen mercedes using gps. michael isikoff , nbc news, boston .
Video on msnbc.com: The 26-year-old who was taken on a wild ride with the two brothers suspected of the Boston Marathon bombings told investigators he found a way to escape when the brothers stopped for gas, and then called police. On Friday, surviving Boston Marathon bombing suspect Dzhokhar Tsarnaev was moved to a medical prison, still unable to speak but declared alert and mentally competent. NBC’s Michael Isikoff reports.