An attorney representing a Lawrence teenager accused of stabbing his grandmother to death said he plans to use the boy’s well-documented mental health history in his defense during the upcoming criminal trial.

Jaered Long, 17, faces a single charge of first-degree murder. He was arrested in December after police found his 67-year-old grandmother, Deborah Bretthauer dead in her apartment with “obvious traumatic injuries.”

Long was 16 at the time of Bretthauer’s death and lived with her in the apartment at 1200 George Court.

On Tuesday morning Long appeared in Douglas County District Court, where he was formally charged as an adult and Judge Kay Huff scheduled his criminal trial to begin in February.

Huff asked defense attorney Branden Smith and Douglas County District Attorney Charles Branson, who is prosecuting Long, how much time they would need for a trial.

When Branson said the timing depended on the defense’s strategy, Smith responded that he planned to use a “mental disease or defect” defense.

During a two-day hearing in September several therapists testified on Long’s ongoing mental health issues.

For years, the therapists said, Long struggled with anger and entitlement issues. He had been seeing a therapist for most of his life and was hospitalized several times before.

Long also struggled with both suicidal thoughts and thoughts of killing his grandmother, one therapist said.

One of Long’s most recent therapists, Loraine Herndon, testified that in 2015 Long’s behavioral problems were worsening and recommended that Bretthauer, who often accompanied him to sessions, consider residential treatment.

Herndon said that Long was becoming increasingly threatening and abusive toward his grandmother.

It is not clear why Long was living with Bretthauer.

After Smith offered a small detail on the defense’s strategy, Huff scheduled a 10-day trial to begin on Feb. 27.

After his arrest in December Long was charged as a juvenile. But on Monday Huff ruled he would be charged as an adult. Factors that influenced her decision included the nature of Bretthauer’s death as well as Long’s criminal and mental health history, which were discussed in detail during the September hearings.

Now that he is charged as an adult, Long faces a life sentence in prison if he is convicted.

Long also faces two additional felony battery charges that have been filed since his arrest in December.

During a two-day hearing in September three Douglas County Juvenile Detention Center corrections officers testified that Long assaulted them.

As of Tuesday morning a criminal charge had not been filed regarding a third alleged battery.

Huff also set Long’s bond at $500,000. If he is able to post bond he is ordered not to have contact with any of the case’s witnesses, excluding his family.

Requests for the arrest affidavit in Long’s case regarding Bretthauer’s death were denied by Douglas County District Court.