Testimony came to a close today in two unrelated Suffolk Superior Court homicide trials as one prosecutor urged first-degree murder convictions for a Roslindale mother accused of killing her two children and another called for the same verdict against a gang member who killed a promising high school student.

Assistant District Attorney Audrey Mark told jurors that ANGELA VASQUEZ (D.O.B. 3/15/76) was a “rage-filled mother” who “killed her two beautiful, innocent children because she simply had enough.”

Vasquez is charged with two counts of first-degree murder for the deaths of her 10-year-old son, Dennis Burgos Jr., and her 13-year-old daughter, Yasmine Burgos, on or about July 29, 2007.

Meanwhile, in another courtroom just one floor above, Assistant District Attorney Masai King told jurors that LAMORY GRAY (D.O.B. 10/15/85) shot Herman Taylor III to death on July 12, 2006, “not because of who Herman Taylor was. He murdered Herman Taylor simply because of where he was.”

Gray is charged with first-degree murder, unlawful possession of a firearm, and unlawful possession of a loaded handgun for the fatal shooting of the 18-year-old Belmont High School student. Affiliated with a gang based on Heath Street, Gray believed – wrongly – that Taylor was a member of the rival H-Block gang, King said.

Mark told jurors in the Vasquez trial that Boston Police officers made a forced entry into the defendant’s Maynard Street home after her therapist contacted authorities and said she feared for her patient’s well-being. After forcing their way in, those officers discovered a “gruesome scene”: Vasquez was bloodied from self-inflicted wounds and was lying next to her son’s badly decomposing body while her daughter’s bloated, decaying remains lay in a nearby bedroom.

“EMTs came in to take care of her, and the knife fell away on its own,” Mark said. “The defendant was conscious – she never lost consciousness.”

Vasquez was rushed to Brigham and Women’s Hospital, where she given various tests, including one that determined that she had not done any damage to her internal organs, Mark said.

Mark recounted for jurors the testimony of the medical examiner, who conducted an extensive medical examination of the children’s remains and determined that no natural disease or condition had caused their deaths. That medical examiner also estimated that Yasmine and Dennis had been dead for at least 12 and seven hours respectively.

Mark told jurors that, just four days before the deceased children were discovered, Vasquez had quit her job after receiving a performance warning from a supervisor.

“She was angry, she was hysterical,” Mark said, referring to the defendant’s emotional state following the loss of her job.

In the days that followed, Mark told jurors, Vasquez wrote a series of haunting entries in her journal, indicating that “The time has come. It’s time for me to leave,” and “The hard part is the children.”

Rejecting the argument that Vasquez was delusional at the time of the crime, Mark said, “There were no delusions. There are no excuses. The defendant made an incredibly tragic decision. She decided that she had had enough, and nothing she could do was good enough. She was going to kill her children.

“The facts of this case tell you, ladies and gentleman, that there is no one to blame but the defendant,” Mark told jurors. “She did murder her children, and she did appreciate the wrongfulness of what she did.”

Upstairs, King ascribed a very different motive to a very different homicide. He reminded jurors of the violent rivalry that fueled dozens of shootings between the Heath Street gang, of which Gray was a reputed member, and H-Block, based near Humboldt Avenue, on which Taylor lived as a noncombatant.

“The shootings were often retaliatory,” King said. “Some witnesses told you about the gang war. The problems between H-Block and Heath Street resulted in violence and sometimes death.”

“There was evidence of that gang war…on the day that Herman was murdered,” King told jurors, drawing their attention to a series of witnesses who claimed memory loss and had to be confronted with their earlier testimony before the Suffolk County Special Grand Jury. “This gang war has created a cloud of fear – not just over Humboldt Avenue – but has also invaded this courtroom throughout this trial.”

Prosecutors allege that Gray climbed out of a distinctive white Nissan Maxima on Crawford Street and approached nearby Humboldt Avenue at about 6:00 that summer evening. Moments earlier, Taylor had left a friend’s house, and was walking toward his home. The two men crossed paths and Gray allegedly called out to him.

Evidence and testimony indicate that Gray began speaking to Taylor in an aggressive and threatening manner. When Taylor turned and tried to run, Gray pulled a gun from his sweatshirt and opened fire.

Mortally wounded, Taylor fell to the ground. A passerby saw him and drove him to a nearby hospital, while the gunman fled down Crawford Street.

“Herman Taylor died from one of the shots fired that night,” King said. “This defendant, Lamory Gray, shot and killed Herman Taylor.”

After closing arguments in the Vasquez case, Judge Patrick Brady instructed jurors on the law and sent them to deliberate. Judge Frank Gaziano likewise instructed jurors in the Gray trial and sent them to deliberate. Neither jury returned a unanimous verdict today and both will reconvene tomorrow.

Vasquez is represented by attorney Janice Bassil and Gray by attorney John Hayes.