In his closing argument this afternoon, a Suffolk County homicide prosecutor said the two defendants charged with murdering a rival and an innocent bystander during a Dorchester shootout acted together and contributed equally to the two victims’ deaths.

“These two are joined at the hip,” Assistant District Attorney John Pappas said, referring to the defendants, EMMANUEL PINA a.k.a. EMMANUEL DePINA (D.O.B. 4/25/83) and SANDRO TAVARES (D.O.B. 12/25/83), both of Dorchester.

“There are only two people out there, and one gun,” Pappas said. “The guy who brought it and the guy who shot it: Sandro Tavares and Emmanuel Pina.”

The defendants are both charged with two counts of first-degree murder, reflecting the Aug. 2, 2009, shooting deaths of Manuel Monteiro, 47, and Jovany “JoJo” Eason, 20, in the area around Ka’Carlos Bar and Grill on Hancock Street. Monteiro worked there as a cook and Eason was a patron.

“There are lines of work in which men and women knowingly put their lives in the line of fire every day,” Pappas said. “Being a chef in a neighborhood restaurant shouldn’t be one of those jobs. It shouldn’t carry with it the risk of being murdered.”

Pappas said Monteiro was standing inside the restaurant and looking out a window when a stray bullet crashed through and struck him in the chest, killing him.

The other victim, Eason, “may have had words with somebody, but no words justify what these two defendants acting together did on that night,” Pappas said. “Emmanuel Pina chased him down with a very specific purpose: to put him down, permanently. That’s exactly what he did.”

Pappas recounted two weeks of testimony suggesting that Tavares and Pina arrived at the restaurant shortly after 12:30 that morning. Tavares went inside while Pina waited outside. An argument between Tavares and Eason ensued, with Pina coming into the restaurant and Tavares leaving. The argument continued in the men’s room, from which Monteiro and other restaurant employees later physically removed Pina and escorted him outside. At that point, Tavares was outside the establishment.

Eason later left the restaurant and approached his car outside. Tavares produced a semiautomatic handgun and pointed it at him, Pappas said, and then gave it to Pina.

“Tavares is not absolved when the gun switches hands to Pina,” Pappas told the court. “That’s intent to kill Jovany Eason, and that intent goes right over to Monteiro … This was not an accident. Their intent was clear.”

Speaking of Tavares, he continued, “He’s the one who contributed in perhaps the most meaningful way by supplying the gun that Pina used to shoot and kill two men.”

After Monteiro was shot in the chest, Pina continued to chase Eason down “literally in cold blood, shooting him in the back and killing him,” Pappas said.

“It was senseless that a gun had to be introduced over a stupid argument about who is hanging with who,” Pappas said. “They had every opportunity to walk away.”

Catherine Rodriguez is the DA’s assigned victim-witness advocate. Pina is represented by attorney James Budreau and Tavares by attorney John Moss. Proceedings were in courtroom 817 before Judge Elizabeth Donovan. Following closing arguments, jurors were instructed on the law; they will resume their deliberations tomorrow.