The defense began presenting its arguments in the penalty phase of the trial of convicted Boston marathon bomber Dzhokhar Tsarnaev yesterday. They’re attempting to save Tsarnaev’s life by linking his crime to his family history. All told, day one brought mixed results. 

In his opening statement, defense attorney David Bruck promised a tale of epic scope.

Bruck spoke of the expulsion of Chechens from their homeland by Joseph Stalin – of the troubled life Dzhokhar Tsarnaev’s parents shared together, abroad and in the US –- and of cultural norms that meant Dzhokhar had to obey his older brother Tamerlan when his father left the family.

But the day closed on an oddly mundane note.

A high-school music teacher described Tamerlan glaring at him when he was booted from the Cambridge Rindge and Latin jazz ensemble due to poor piano skills.

That story — which occurred nearly nine years before the marathon bombings — may not have the defense’s attempts to cast Tamerlan as a domineering, hypnotic influence.

But jurors also heard from the mother and best friend of Tamerlan’s wife, Katherine. Both said her life transformed after they met: she got pregnant, dropped out of college, converted to Islam, and began wearing a head scarf and proselytizing.