EVERETT — A Monroe inmate was sentenced Wednesday to nearly 24 years in prison for his failed attempt to kill another inmate in 2009.

Daniel Perez already is serving a 30-year sentence for the 2006 strangulation death of his cell mate. He will begin his new sentence only after he’s done his time for the murder. Perez is 26.

Snohomish County Superior Court Judge Anita Farris on Wednesday found no reason to cut Perez a break. She said his criminal behavior already cost two people their lives. Perez was serving time for a vehicular manslaughter conviction in 2006 when he strangled Cory Garinza with the drawstring from his prison-issued sweatpants.

“It’s just pure luck we don’t have a third dead person,” Farris said.

A jury in October found Perez guilty of attempted second-degree murder for the 2009 attack. Prosecutors alleged that Perez wrapped a piece of cloth around another inmate’s neck and pulled the ligature until the man lost consciousness.

Perez walked back to his cell in the special offenders unit at the Monroe Correctional Complex.

When the victim regained consciousness, he emerged from the laundry room and waved at corrections staff.

After the assault, Perez told corrections officers that God was making him do things and he began to yell about Satan, court papers said.

No clear motive for the attack was ever found.

“This was a carefully prepared attack,” Snohomish County deputy prosecutor Tobin Darrow said. “It was carried out in a very cold-blooded fashion.”

Darrow argued for a high-end sentence.

Initially, the prosecutor believed that a conviction would be Perez’s third-strike under the state’s persistent offender act. Darrow later learned that the vehicular homicide was charged under the theory that Perez disregarded the safety of others. Under that theory, a vehicular homicide conviction doesn’t count as a strike offense, Darrow explained.

Defense attorney Caroline Mann disputed the prosecutor’s characterization of the strangulation attempt. She pointed out that beginning part of the attack was carried out in full view of security cameras and there was no possibility that Perez would get away with the assault. There was no animosity between the two men. Something else was going on that day, she said.

“This is not an individual who is acting out for the sake of acting out,” Mann said.

Her client has long-standing significant mental health problems, she said. He has attempted suicide numerous times and most of his outbursts are directed at himself, she said.

“This is an individual who struggles with mental illness on a daily basis,” Mann said.

She tried to convince the judge the Perez was suffering from a psychotic break when he attacked the other inmate. For that reason, she asked Farris to show Perez leniency and sentence him to nine years for murder attempt. That’s well below the standard range.

Perez’s mother told the judge that her son likely was undergoing yet another change in his medication regimen at the time of the assault. She said there have been ongoing inconsistencies with his treatment while in prison.

Her son has the love and support of his family, including his five siblings, the mother said.

“We’d like to see him out at some point, even if it’s when he’s in his 60s,” she said through tears.

Farris found that Perez’s mental health issues didn’t justify a sentence below the standard range.

The 24-year sentence is “well-deserved in this case,” the judge said.

Diana Hefley: 425-339-3463; hefley@heraldnet.com.