A prosecutor Tuesday began his closing argument in the trial of Edwin Ramos by attacking the credibility of the defendant, who testified in his own defense in his trial on charges that he killed a father and his two sons in San Francisco in 2008.

"The defendant is asking you to believe the unbelievable," Assistant District Attorney Harry Dorfman told jurors. "How can you trust Mr. Ramos' credibility when he lied about so much?"

Ramos, 25, of El Sobrante, is accused of fatally shooting Tony Bologna, 48, and his sons Michael, 20, and Matthew, 16, near Maynard and Congdon streets in the city's Excelsior District on June 22, 2008.

Dorfman alleged again during his closing argument this morning that Ramos shot the Bolognas after mistaking them for rival gang members and that the killings were in retaliation for a shooting earlier that day that injured another MS-13 member.

Ramos testified earlier in the trial that he left the gang in 2006 but remained friends with gang members, including Wilfredo "Flaco" Reyes, who he said fired the shots at the Bolognas from a car Ramos was driving. Reyes remains at large.

Dorfman pointed out today that Ramos initially told police that he was at home in El Sobrante at the time of the shooting before changing his story once he was presented with incriminating evidence by homicide inspectors.

"When the details that come out of his mouth keep changing, does he care what lies he tells? Does he care how many lies he tells? Apparently he doesn't," Dorfman said.

Ramos said during his testimony that he was still in contact with many MS-13 gang members because he began selling cocaine in 2007 to financially support his young daughter.

But Dorfman pointed out that instead of spending money on his daughter, Ramos earlier in 2008 spent $14,000 on a new Chrysler 300, the one that would ultimately be used in the shooting.

He said Ramos' story of selling drugs was a ruse "to give a non-gang spin to the evidence of his daily gang connections."

"Don't be fooled by this man," he said.

Dorfman juxtaposed Ramos' testimony with that of Andrew Bologna, who was in the car with his father and brothers and was the only one to survive the shooting.

"The defendant and Andrew Bologna, they both can't be right," he said.

Andrew Bologna testified earlier in the trial that he saw Ramos give a mean look to his father and then open fire as he pulled the Chrysler 300 alongside the Bolognas' Honda Civic.

In the couple of days after the shooting, he also helped police come up with a sketch of a suspect who looked very similar to Ramos.

"He did a damn good job of describing the details of the man who shot his father and brothers," Dorfman said. "He was consistent, accurate and honest."

Danielle Bologna, the wife and mother of the victims, was in court today and has sat through most of the trial, which started in January.

Dorfman is continuing his closing argument this afternoon and will be followed by defense attorney Marla Zamora.

Zamora said outside of court this afternoon that she's "going to say to the jury what really happened, without any twists or turns."

She said she will concentrate her arguments on the whereabouts of Reyes, who is believed to have fled to somewhere in South Carolina following the shooting.

"Where's the shooter? Where's 'Flaco'? Why isn't he sitting here? That's the big question that the jury should focus on," she said.