Prosecutor Allan J. Webster called the killings on the middle school ball fields "a massacre" and "a blood bath."
One victim was stabbed so many times that the medical examiners conducting his autopsy spent a day photographing and documenting his 151 wounds.
And a man who saw the stabbings was so terrified to testify against the MS-13 gang member he knew only as "Lil' Diablo" that his body shook on the witness stand.
Jurors took two hours yesterday to convict the gang member, Enrique Ricardo Pizzaro Silva, of first-degree murder in the deaths of two men who unknowingly flashed the hand gestures of a rival gang at a Baltimore club in January 2006.
"The biggest mistake they made," Webster told jurors in his closing argument, "was drinking way too much and making the fatal mistake ... of telling MS-13 gang members that they were 18th Street [gang members]. When that was said, it was done. There was no decision to be made. They had to be killed."
A police detective testified that the rivalry between the gangs is so deep that MS-13 members have standing orders to harm any 18th Street member they see.
The attacks should be committed, if possible, "with an edged weapon - because it's more personal," said Detective Claudio Saa, who works in Herndon, Va., and trains law enforcement officers on the Salvadoran gang known as Mara Salvatrucha, or MS-13.
Baltimore County police have said the deaths of Herrim Geovanny Alverez Salmaron and Hever Joel Gonzalez Garcia, who were not associated with any gang, were the first MS-13-related killings in the county. Their bodies were found Jan. 8, 2006, on the fields of Arbutus Middle School.
Defense attorney Sharon A.H. May agreed that the deaths were horrible. She argued that the testimony of an MS-13 member who admitted helping stab the men was uncorroborated and motivated by the convicted killer's desire for a shorter prison sentence. And she told jurors that the testimony of two nongang members should also be discounted, characterizing them as accomplices who had done nothing to stop the killings that occurred in front of them.
But Webster countered that the witnesses - including one with a scar from his eye to his ear from an attack by MS-13 gang members when he was 13 and living in El Salvador - were understandably terrified.
"It's no wonder why he didn't run off and get the police," the prosecutor said.
Pizzaro Silva could receive life in prison without the possibility of parole when he is sentenced.