Two juries have begun their deliberations after unrelated Suffolk County murder trials, both of which relied on witness observations to identify the defendants, District Attorney Daniel F. Conley said.

Separate Suffolk Superior Court juries are weighing the fates of BRIAN LEE (D.O.B. 9/14/63), charged with first-degree murder for the fatal beating and subsequent dismemberment of his father, Edward Lee, in Mattapan and MARIO MARTINEZ BONILLA (D.O.B. 6/1/86), likewise charged with murder one for the fatal stabbing of Luis “Tito” Garcia-Calle in Chelsea.

“On Oct. 25, 2006, 70-year-old Edward Lee, Jr., walked out of Dorchester District Court with a restraining order against his younger son,” Assistant District Attorney Holly Broadbent said this morning in her closing argument. Forty-eight hours later, Edward Lee’s body was in pieces in different trash bags across the city.”

Broadbent told the jury and spectators in courtroom 815 that a witness saw the younger Lee deposit several white trash bags into bins behind her Homestead Street home on the night of Oct. 28, 2006. When that witness and her daughter pulled the bags from the bins and looked inside, they discovered the dismembered limbs and decapitated head of Edward Lee.

Broadbent told the court that Brian Lee brutally bludgeoned his elderly father to death as he lay in his bed inside his Hollingsworth Street home, then “used a power saw to dismember and decapitate his own father.” Broadbent said the defendant then wrapped his father’s torso in garbage bags and dragged it to the victim’s basement, where he placed it in a plastic bin. After that, the defendant “nonchalantly tried to dispose his father’s remains in [the female witness’s] backyard.”

That witness, Broadbent said, “was 100% sure that the man sitting in front of you dropped off those bags with the remains inside.”

Calling the father-son relationship “dysfunctional,” Broadbent told jurors that autopsy results, evidence analyzed by criminologists, and the defendant’s own admissions all pointed to the defendant’s guilt.

Urging jurors to convict Brian Lee of first-degree murder under the theory of extreme atrocity and cruelty, Broadbent recounted the severity of the attack on Edward Lee.

“Look at the autopsy report of Edward Lee. He suffered repeated blows to the head, his skull was fractured in multiple places, his ribs were fractured, his body was covered in contusions and bruises,” she said.

Across the hall in courtroom 808, Assistant District Attorney Ian Polumbaum told jurors to remember the testimony of witnesses who identified Bonilla as the man who stabbed the 22-year-old Garcia-Calle to death after being kicked out of a Williams Street bar.

Bonilla “brought a knife to a fistfight, luring a man to his death,” Polumbaum said, because “he knew he was going to win.”

Prosecutors allege that on Feb. 27, 2008, Martinez Bonilla, of Salvadorian heritage, walked into El Carriel – a bar popular with members of Chelsea’s Colombian community – and “made the decision to mouth off about Colombians in a Colombian bar.”

Sensing tension, bar staff asked Martinez Bonilla to leave the bar. The defendant left the bar, Polumbaum said, but not before he challenged Garcia-Calle to join him outside, suggesting that he “invited, welcomed, and expected” the opportunity to engage in combat with the victim.

The two men became engaged in a physical confrontation outside that turned deadly when Martinez Bonilla produced a knife and stabbed Garcia-Calle four times before fleeing. Witnesses called emergency medical services, and the victim was rushed to Massachusetts General Hospital for treatment, where he remained until he succumbed to his injuries on March 17, 2008.

A break in the case came on June 5, 2008, when Martinez Bonilla allegedly returned to El Carriel and began drinking heavily. Bar staff recognized him as the man who had fought with Garcia-Calle and called police; when they arrived, he was so intoxicated that he could not speak with them. He was taken into protective custody. In the days that followed, investigators obtained multiple identifications of Martinez Bonilla as the assailant and Suffolk prosecutors approved a warrant charging him with murder on June 10.

“Luis Garcia-Calle died because of the decision to use deadly force by this defendant,” Polumbaum told jurors. “And that, ladies and gentlemen, is murder.”

Lee is representing himself with the assistance of defense attorney Denise Regan; Bonilla is represented by attorney Michael Laurano. Superior Court Judges John Cratsley and Charles Spurlock instructed the respective juries on the relevant law early this afternoon before releasing them to begin their deliberations.

Katherine Moran is the DA’s victim-witness advocate in the Lee case and Eliany Colon-Vargas is the advocate assigned to the Martinez Bonilla case.