Through surreal photos of Chiara Levin’s blood splashed across the back seat of a Cadillac Escalade, her father, an art history professor in Kentucky, pen in hand and glasses perched on his nose, calmly observed the theater of a downtown courtroom yesterday as though preparing a grade.

But when Boston police officer Ronnie Fabiano described how a nurse at Boston Medical Center called Levin’s wife, Maria, two years ago to tell the couple their 22-year-old daughter had been fatally shot, and the nurse held the phone to an unresponsive Chiara’s ear so her mom could whisper goodbye, William Levin shuddered and sobbed.

Prosecutor Ed Zabin, on opening day of Casimiro Barros’ murder trial, cautioned a Suffolk Superior Court jury that he would expose them to “an imperfect slice of life.”

On the night of March 23, 2007, when Levin, an assistant at a Manhattan public relations firm in Boston for her aunt’s 90th birthday party, met two chums from the University of Michigan and her cousin Elizabeth Koch at the Caprice Lounge, “She was a beautiful young woman, full of life, full of energy,” Zabin said, “and by dawn she was dead.”

Levin was killed after accepting an invitation from three strangers she met outside the club to attend an after-hours house party in Dorchester. One of them, Manuel “Spank” Andrade, 35, who is being tried separately for murder, is alleged to have gotten into a street shootout with reputed gangbanger Barros, 22, after throwing a plate of rice and shooting Barros’ buddy.

Levin was shot in the head when a stray bullet shattered a window of the SUV she arrived in.

Zabin said Barros had “malice in his heart and a gun in his hand.”

But Barros’ defense attorney, Christopher Belezos, told jurors Zabin will have a tough time proving it. Only one witness out of three dozen people at the party puts Barros behind the murder weapon.

“You may have to put aside the tragic death of a young girl,” Belezos said, “and view (the evidence) in the cold light it deserves.”