Morgan Lane Arnold, 14, will be tried as an adult in the stabbing death of her father, a judge ruled Monday. (Courtesy of Howard County Police Department)

A Howard County judge sent Morgan Lane Arnold back to jail from a juvenile facility Monday, ruling that the 16-year-old should be tried as an adult on charges that she plotted with her boyfriend to kill her father.

Circuit Judge William Tucker told a full courtroom that Arnold — accused of helping to plan the May 2013 killing of her father, Dennis Lane — needs intensive mental health treatment. There’s no guarantee she would receive that treatment in the five years she might spend in the juvenile system if found guilty, Tucker said.

Arnold was a few months shy of her 15th birthday when her then-boyfriend, Jason Bulmer, now 21, entered Lane’s Ellicott City home in the early morning through a basement door that Arnold had left unlocked. In the home, Bulmer fatally stabbed Lane, a well-known businessman and blogger.

Bulmer, whose attorneys described him as intellectually limited, was sentenced to 30 years in prison last month after pleading guilty to first-degree murder.

If her case were sent to juvenile court, Arnold could be released by age 21. If tried and convicted as an adult, she could be sentenced to life in prison for first-degree murder and other counts.

“If she’s not treated properly and has to be released in five years, that is not in the best interest of society,” Tucker said.

After the ruling, Arnold’s attorney, Joseph Murtha, tried to enter a plea that Arnold is not criminally responsible for her actions because of her mental state. Tucker rejected it, ruling that the plea was not filed in a timely fashion.

In the past two weeks, Arnold read books and had stuffed toy animals with her in the courtroom as her attorneys sought to have her case moved to juvenile court. They argued that she suffers from profound mental illness — she has been diagnosed with Asperger’s, attention-deficit disorder, anxiety and depression, among other conditions — and said she has the emotional capacity of a child. Defense witnesses portrayed her as sickly and childlike.

But prosecutors said Arnold thrived on violent fantasy and wanted to kill people who upset her, and they called the stuffed toy animals props. Arnold’s attorneys alleged that Bulmer manipulated her, but prosecutors said electronic messages between the couple show that she was the one in control of the relationship.

On Monday, a black-and-white stuffed toy pony lay on the defense table in front of Arnold, who wore glittery flat shoes and white socks pulled up over her calves. She read a book of anime nearly the entire time Tucker spoke.

“She has been totally disinterested in these proceedings,” Tucker said.

Arnold will return to the Howard County Detention Center.

Murtha called the ruling disappointing. “I’ve spent enough time with Morgan Arnold to believe she’s a child who has profound mental health problems, who will not fare well in the adult penal system if she’s found guilty,” Murtha said.

— Baltimore Sun

Get updates on your area delivered via e-mail.