A board denied parole Friday for a former Redwood City resident who smothered her aging husband with a pillow in 1999, telling police he had become "too much of a burden," according to the San Mateo County District Attorney's Office.

Rosa Ana Manrow was 45 when she killed her 78-year-old husband, Warren Manrow.

"She talked about it being a mercy killing, but we always felt at the time that it was more motivated by 'I am tired of taking care of him,'" District Attorney Steve Wagstaffe said. "She was younger than him."

Manrow had also compared herself to Jack Kevorkian, the now-deceased doctor who gained national notoriety for helping terminally ill people commit suicide during the 1990s, according to prosecutors.

In August 2000 a jury found Manrow guilty of second-degree murder; she was sentenced to state prison for 15 years to life. She is incarcerated at the Central California Women's Facility at Chowchilla.

On Friday, a two-person Board of Parole found Manrow "unsuitable for parole," according to the district attorney's office. Her next parole hearing will be in five years.

Wagstaffe said he was told by one of his prosecutors that the two main factors cited against Manrow's release during Friday's hearing were an undisclosed violation of prison rules and her "lack of insight" into the crime.

"They all mouth the right thing," Wagstaffe said. "But it was clear she wasn't fully grasping of the gravity of the crime."

Manrow's defense attorney, Jeff Boyarsky, could not be reached for comment Monday.

Email Bonnie Eslinger at beslinger@dailynewsgroup.com; follow her at twitter.com/bonnieeslinger.