VISTA -- Claudia Sinkule stared at the man who murdered her daughter, the man who struck Nicole "Nicci" Sinkule in the head 13 times with a claw hammer. A prepared statement in hand, the woman read only one sentence, then set it aside.

"Every day, I wake up with panic attacks. Every day I vomit," she said spontaneously. "My arms, they want to hold Nicole so bad."

Eric Nathanial "Nate" Marum stared straight ahead, toward the front of a Vista courtroom, as she spoke.

"Why, Nate? Why? I loved her so much," Claudia Sinkule said. "I'm not ready to forgive you yet."

Claudia Sinkule told Marum of her pain at losing 24-year-old Nicole, told him how she still, 15 months later, finds herself crawling on the floor, wracked with grief.

"I have her jewelry on. I have her blouse on. I have her shoes on," Claudia Sinkule said, grabbing at her pink shirt and looking at Marum.

Shortly after Claudia Sinkule's anguished turn at the podium, Superior Court Judge Joan Weber handed Marum a sentence of 16 years to life in prison -- a punishment he received in exchange for his guilty plea to second-degree murder for the Oct. 16, 2005, slaying of his girlfriend at her Oceanside residence.

Marum would have faced 26 years to life in prison if he had been convicted of first-degree murder at trial.

It's a far cry from his life just five years ago. Court documents state Marum earned a bachelor's degree in psychology from the University of California, Los Angeles, in 2002, where he was a track athlete with Olympic aspirations. He was also once a National Merit Scholar semi-finalist.

Marum began using methamphetamine in February 2004, according to his probation report in the court file. That same report states a county forensic doctor who twice interviewed Marum deemed that the young man may have been suffering from a "methamphetamine-induced psychosis" when he killed his girlfriend, a woman who was trying to end the relationship, but kept returning to it.

On Friday, dressed in a blue jail uniform and handcuffed to his chair, Marum apologized to the family of the woman he killed.

"I laughed at Nicole the first time she told me life was beautiful," the 28-year-old said, "and I fell in love with her when she showed me it was true."

Marum's voice quivered as he asked forgiveness from her mother, her father, her sister.

"There is no one to blame but myself, and no one who suffered more than Nicole," he said.

In the early morning hours before she was found dead, police responded to a call about an incident at her home. Nicole Sinkule told the responding officers there was no physical violence during the incident, according to an affidavit filed with the court, so no arrest was made.

Three hours later, at 4:45 a.m., officers returned to the North Nevada Street apartment in response to a call from Sinkule's neighbor. Nicole Sinkule was dead.

Police found and arrested Marum an hour later. Court documents state that he told police he went to his girlfriend's apartment, where he grabbed the claw hammer from his tool box. He went back and forth a few times, he said, before finally going in and killing her in her bed, the filings state.

During the sentencing hearing, Sinkule's family told Marum they plan to be at his parole hearings, plan to argue that he never be released.

Before handing down the sentence, Judge Weber said the case was "a case study in the devastating effects of domestic violence."

"The criminal justice system was not able to save Nicole," Weber said. "The criminal justice system was incapable of convincing her of getting as far away from Nate as she could."

Violence -- and Marum's methamphetamine use -- plagued the 13-month relationship, including an incident in which Marum tried to physically pull Nicole Sinkule away while she was on duty as a waitress in a harborside restaurant. Police were called; Marum jumped in the water and tried to hide.

Marum pleaded guilty to charges related to that incident and other instances of domestic violence against the young woman.

A protective order keeping Marum away from Nicole Sinkule was lifted just four months before the killing -- at a June 3, 2005, hearing at which Nicole Sinkule told the judge she wanted to live with Marum.

During Marum's sentencing hearing Friday, a friend of Nicole Sinkule's spoke of Sinkule's heartache over the relationship with Marum.

"She always told me it was in her best interest to leave Nate," Michelle Morin said. Later, speaking about their last conversation, Morin said, "This time she said his good qualities outweighed his bad.

"Things like this don't happen. People don't kill other people with a hammer while they sleep."

Marum's younger brother and parents, who spoke at the sentencing hearing, pointed to his methamphetamine use.

"It became clear that the drugs were significantly changing his personality," brother Barrett Marum said. "I don't think it excuses his actions, but I do think it explains them."

Mother Georgia Marum said her son is "paying the price for disbelief in his chemical vulnerability."

Since their daughter's murder, Claudia and Glenn Sinkule have established a foundation to help combat domestic violence. Information can be found at www.nicolesinkule.org

Contact staff writer Teri Figueroa at (760) 631-6624 or tfigueroa@nctimes.com.