Two or more years before Malik Vincent Murphy allegedly stabbed his two youngest siblings to death, he hid out in a bathroom at his high school in Lincoln, Neb., waiting to strangle the next person who walked through the door.
The scheme, which apparently fizzled when he lost his nerve, was described in 4th Judicial District Court on Friday as an early instance of "homicidal ideations" that culminated Oct. 17 when police say Murphy grabbed a hunting knife and killed brother Noah, 7, and sister Sophia, 5, as they lay sleeping.
"I can't stop thinking about killing people," the 20-year-old told a Colorado Springs police detective in a low, even voice during a videotaped interrogation shown in court.
Sitting at a small table opposite the detective, Murphy said that killing his siblings was "something that (he) had to do." At one point, Murphy said he didn't know why. At another, he said he wanted to kill everyone in his house, and offered a chilling explanation: "To be by myself."
Murphy's history of violent thoughts and mental health struggles - including as many as three commitments to one Colorado Springs psychiatric facility - emerged as prosecutors laid out the evidence against him at a three-hour hearing. Murphy's parents sat in a front row in court, his mother sobbing into a tissue as a police witness described the children's fatal injuries and crime scene photos displayed the grisly aftermath.
The children died of multiple stab wounds each despite family members' attempts to stanch their bleeding, authorities said.
Their father, Jefferson "Vinny" Murphy, survived a stab wound in the neck. He told police that his son attacked him as soon as he walked out of his bedroom to investigate his daughter's frantic screams.
At the hearing's conclusion, presiding Judge G. David Miller ordered Murphy to trial on two counts of first-degree murder and one count of attempted first-degree murder, as well as sentence enhancers related to his use of a weapon.
Murphy, a Pikes Peak Community College student at the time of the attacks, lived with his parents, grandmother and four siblings in a small ranch-style house at 912 Carlisle St., near Interstate 25 and Fillmore Avenue in central Colorado Springs.
The investigator who questioned him on tape, detective Jerry Schiffelbein, said the family had moved to Colorado Springs from Lincoln several years earlier seeking a "fresh start."
The move came on the heels of an incident in which Murphy lay in wait inside a bathroom at Lincoln Southeast High School intending to strangle a classmate, Schiffelbein said. Malik Murphy told people he wanted to know what it felt like to kill, but didn't follow through because he worried that his intended victims would fight back and overpower him.
The incident, which was investigated by Lincoln police, caused Academy School District 20 to draft a special safety plan when Murphy enrolled in a vocational school affiliated with Rampart High during the 2014-15 school year, Schiffelbein told the court.
In laying the groundwork for a mental health defense, his public defenders asked Schiffelbein about moments that were trimmed out of the interrogation video, including Murphy banging his head against the wall or lying on the floor, repeating to himself, "no, no, no," "Oh my God, why?" and "Malik, what did you do?"
Murphy told police he had been treated at six or seven psychiatric facilities, and that he had gone three times to AspenPointe's Lighthouse in Colorado Springs, which operates a "short-term stabilization center."
In April 2016, a therapist at Highlands Behavioral Health in Littleton contacted the Department of Human Services to report that Murphy had spoken of killing his entire family with a kitchen knife. The mental health worker was concerned that Murphy's mother wasn't taking his threat seriously, which prosecutors disputed during the hearing.
Last March, Murphy borrowed his parents' Ford Explorer to go to a job interview but didn't come home. He was later arrested in Effingham, Ill., as he stood watching the flaming SUV after setting fire to it on the side of a road, authorities say. Arson charges were dismissed in exchange for his agreement to abide by a mental health treatment plan and to continue taking prescribed medications.
During a search of the Murphys' home, authorities found mental health records stowed in a plastic bin along with a prescription for Malik Murphy being kept in his parents' bedroom, a generic version of Zoloft, which is commonly prescribed for depression.
Under questioning by police, Murphy said he had been diagnosed with depression and anti-social personality disorder, which is associated with homicidal and suicidal thoughts and characterized as a lack of regard for the rights and well-being of others.
"Early, effective and appropriate discipline," behavior modification and psychotherapy factor into treatment of the condition, according to the Mayo Clinic.
One mental health worker also thought he had bipolar disorder, Malik Murphy told police.
Murphy acknowledged that he hadn't regularly been taking his depression medication and that he had been thinking about killing family members "for months."
Police say he purchased his hunting knife from Walmart several months earlier and kept it near his bed.
Murphy is due to be arraigned April 9, at which time a trial will be scheduled.