Defense attorneys for Brittany Norwood, the woman charged with killing a co-worker in a Bethesda yoga shop, are likely to assert that their client is not criminally responsible because of mental illness, according to a filing in Montgomery County Circuit Court.

The lawyers also asked a judge to postpone Norwood’s October trial so they can further investigate her medical, social and educational background.

Norwood, 29, is charged with first-degree murder in the March killing of Jayna Murray, 30, inside Lululemon Athletica in downtown Bethesda. Prosecutors have said they will seek a sentence of life without the possibility of parole if Norwood is convicted.

In Maryland, the so-called “insanity defense” is known as NCR, or not criminally responsible. It holds that because of a mental disorder or mental retardation, suspects may lack the capacity to appreciate that their conduct was illegal or can lack the capacity to “conform that conduct to the requirements of law,” according to statutory definitions. If a defendant is found not criminally responsible, they may be committed to a psychiatric institution.

Norwood’s attorneys “believe that an NCR defense is warranted, and an NCR plea is likely,” the lawyers, Douglas Wood and Christopher Griffiths, wrote in the filing, submitted Friday and made available at the courthouse Monday.

Norwood initially told police that she and Murray were attacked and sexually assaulted by two masked men who slipped into the store after closing time March 11. But as forensic evidence piled up against Norwood, detectives began to doubt her story and alleged that she attacked Murray, and then injured herself and tied herself up as part of a coverup.

Norwood is college-educated and bright; her attorneys would have to show evidence of mental illness if they pursued the insanity defense.

Her attorneys said in court papers that they have retained a forensic psychiatrist and are “interviewing any person who has had a significant relationship with” Norwood.