Sixteen times, Deputy District Attorney Mark V. Tranquilli pounded a ledge in front of the jury box with his fist yesterday, once for each stab wound suffered by 16-year-old Demi Cuccia.

Mr. Tranquilli used his closing argument to forcefully illustrate the point that the most damning piece of evidence against John Mullarkey Jr. in deciding whether the case was a deliberate, premeditated murder was the most obvious -- Demi's body.

John Mullarkey

Demi Cuccia

"All this nonsense about Accutane -- the Boogeyman -- and diminished capacity," Mr. Tranquilli said, referring to the defense's argument that Mr. Mullarkey became depressed after quitting the acne drug, "that's a bunch of malarkey."

The jury took just 45 minutes of deliberation to agree, convicting Mr. Mullarkey, 20, of Monroeville, of first-degree murder. He was sentenced immediately to life in prison without the possibility of parole by Common Pleas Judge Jeffrey A. Manning.

The verdict was a rejection of the Accutane defense proffered by defense attorney Robert E. Stewart, who argued that Mr. Mullarkey's mind was in a tempest over the failed relationship -- a condition exacerbated by the acne drug. It was believed to be the first Accutane was cited as part of a homicide defense.

The two sides called competing experts to testify about Accutane's side effects, and Mr. Stewart drew upon reports and Food and Drug Administration-mandated labels warning of depression and suicide. Mr. Mullarkey survived a suicide attempt shortly after the stabbing, when he slit his throat.

But Accutane has never been definitively linked to such problems, said dermatologist Mark Seraly of Peters, who testified for the prosecution that Accutane patients actually commit suicide at one-fourth the rate of their age group.

On Friday, Accutane's Switzerland-based manufacturer, Roche Holding AG, announced it was pulling Accutane from the market. Mr. Stewart yesterday filed a motion for a mistrial because of new evidence and said he would seek an expert witness to testify to why the drug was yanked.

Judge Manning denied the motion because Roche said it pulled the drug for economic reasons. The market share of Accutane has waned in recent years as generic versions have become available, the company said, also citing expensive lawsuits filed against the company based on Accutane's side effects.

Because the company didn't say it was pulling the drug for safety reasons, Judge Manning said it was just a coincidence that didn't impact the case.

In an interview after the verdict, Mr. Stewart said he will continue that fight on appeal. He said the FDA often investigates the real reasons behind why a drug was pulled from the market -- and Mr. Stewart will petition the FDA if it doesn't act swiftly.

"I told [Mr. Mullarkey] that to consider this just as the beginning of your case," Mr. Stewart said.

The case began Aug. 15, 2007, the day after Demi, a Gateway High School cheerleader, turned 16, when she invited Mr. Mullarkey to her Monroeville home, apparently to talk about their rocky relationship.

In his closing, Mr. Stewart described his client in those moments as "a scared, a confused and an upset 18-year-old boy that went over there with an intention of being with a girl he loved."

Mr. Mullarkey later told psychiatrists that the two got into a shouting match and that he remembered pulling his 3.5-inch pocket knife from his pocket, but didn't remember the stabbing.

Mr. Tranquilli asked jurors for a first-degree conviction -- and not third-degree, which carries a maximum sentence of 20 years to 40 years in prison -- because the 16 stab wounds were evidence of premeditation, which can be formed in an instant.

Testimony identified little warning for the outburst, and members of the Cuccia family after the verdict said they hope a foundation established in Demi's name will raise awareness about teen dating violence and help potential victims identify warning signs.

The Cuccias sighed with relief at the verdict and offered tearful statements to reporters afterward.

Jodi Cuccia, Demi's mother, cited testimony that Mr. Mullarkey never showed remorse.

"I couldn't imagine someone being capable of what he did and having no emotion about it," she said.

Throughout the four-day trial, Mr. Mullarkey trembled and, at times, wept, staring off into a corner of the courtroom.

But as he stood yesterday to face his verdict and life sentence, Mr. Mullarkey was motionless. Mr. Stewart said he advised his client not to say anything before sentencing because it might interfere with the appeal, so Mr. Mullarkey offered only "yes," when asked if he understood his appellate rights.

As sheriff's deputies led the shackled Mr. Mullarkey from the courtroom, his father, John Mullarkey Sr., said, "We're with you, buddy." Other supporters called out, "I love you."

The newly convicted murderer never turned and never flinched, his eyes trained straight ahead.