Investigators now have some solid leads to follow in Monday's deadly bombing at the finish line of the Boston Marathon.  And the identity of the third victim of the attack is now public:  Lingzi Lu was a graduate student in math and statistic at Boston University

On the day before the marathon, Lingzi learned she had passed the first half of her comprehensive master's degree exams and needed only one more course to complete her degree in statistics.

Tasso J. Kaper, chairman of BU's math and statistics department said, “She's a very bright young scientist. Enthusiastic, very bubbly, talkative.  Her friends are going to miss her deeply.”

The other fatalities were 8-year old Martin Richard and 29-year old Krystle Campbell, both of the Boston area.

Authorities have a better idea of who planted the bombs (which led to some false reporting).  A security camera from the posh Lord And Taylor department store reportedly showed a man walking to the crime scene while talking on a cell phone, putting a package in a black bag and then placing it at the second explosion location and then quickly walking away.

Meanwhile, investigators are combing through forensic evidence, including the remains of the pressure cookers used to house the bombs; a piece of circuit board believed to have been used for the triggering device; and a Tenergy brand Sub-C 3000 battery pack that powered the circuit board.  The Tenergy Company of Fremont, California released a statement saying it is “appalled” that the bomber used its product.  Tenergy also says it sells 10,000 of the units annually.