The state’s highest court ruled Tuesday that a Dorchester man may have been too drunk to be convicted of first-degree murder on grounds of extreme cruelty in the stabbing death of his girlfriend after the couple celebrated Valentine’s Day.
In a 5-0 ruling, the Supreme Judicial Court said the Suffolk Superior Court jury that convicted Mario Gonzalez reached its verdict after being given legally flawed instructions on how much weight they could give to Gonzalez’s alcohol consumption before he killed Luz Forty, his girlfriend.
“The judge did not instruct the jury that they could consider any credible evidence of the defendant’s consumption of alcohol in determining whether the defendant committed the killing with extreme atrocity or cruelty,’’ Chief Justice Ralph Gants wrote.
The failure of then-Superior Court Judge Geraldine S. Hines to link Gonzalez’s alcohol consumption to its impact on Gonzalez’s state of mind means the first-degree murder verdict cannot stand, Gants wrote.
(Hines joined the Supreme Judicial Court last month and was not part of the SJC proceedings.)
“The judge’s instructions on intoxication would have been understood by the jury to relate only to the elements of premeditation and malice, and not to whether the defendant acted with extreme atrocity or cruelty,” Gants wrote. “The absence of such an instruction was error.’’
Boston police responding to Gonzalez’s apartment early on Feb. 15, 2009, found the 39-year-old Forty lying on a bed in a bedroom covered in blood, except the floor, which had been mopped clean. Gonzalez told police an intruder had attacked Forty, the SJC said.
“‘Please don’t let me die,’” Forty told first responders, according to the court. “‘I don’t want to die.’”
Before she died from multiple stab wounds to her torso, while being rushed to a Boston hospital, Forty identified Gonzalez as the person who stabbed her at least six times, according to the decision.
After its ruling, the SJC said Suffolk District Attorney Daniel F. Conley’s office can seek to retry Gonzalez for first-degree murder or allow him to remain behind bars, convicted of second-degree murder, which carries the possibility of parole after 15 years imprisonment.
First-degree murder carries a mandatory sentence of life imprisonment without parole.
Jake Wark, a spokesman for Conley, said prosecutors are now reviewing their case files to see whether the evidence and witnesses used during Gonzalez’s trial would be available for a second trial.
“The facts of this case warrant a first-degree conviction,’’ said Wark. “We’re reviewing the current status of the case, witnesses, and evidence before determining our next step.’’
Gonzalez’s appellate attorney, David Keighley of Fairhaven, declined to comment.John R. Ellement can be reached at ellement@globe.
com. Follow him on Twitter @JREbosglobe.