The state’s youngest manslaughter defendant in at least 25 years will appear Thursday in Skowhegan District Court, where attorneys will present arguments about whether she is competent to stand trial.

Kelli Murphy, now 12, of Fairfield, was charged in September 2012 with the manslaughter of 3-month-old Brooklyn Foss-Greenaway, of Fairfield, who died at the home of Murphy’s mother, Amanda Huard, in July 2012.

In March 2013 and again in June, the court found Murphy was not competent to stand trial, but that she was expected to become competent in the foreseeable future.

Psychologists working for the state and Murphy’s defense team have been evaluating Murphy ever since, to monitor changes in her level of competence.

In order to be found competent, defendants must understand fully the charges against them and how those charges relate to their actions, among other concepts.

Murphy’s lawyer, John Martin, said the defense’s psychologist, Dr. Carlann Welch, was not ready to present her findings in January, which led to a postponement of the hearing. Martin said the defense team now is fully prepared for Thursday’s hearing, which will be closed to the public.

The state’s chief forensic psychologist, Dr. Debra Baeder, also will testify.

Martin said Murphy has shown no growth in certain areas that are critical to achieving competence, but Assistant Attorney General Andrew Benson said the state believes Murphy now has the required skills.

Martin said he also will argue that the case against Murphy be dropped, because there is no way to know whether Murphy will become competent in the future.

“The whole idea of the court system is not to keep juveniles in limbo,” he said.

If the judge, Charles LaVerdierre, agrees that Murphy is not competent, he could dismiss the case or order that she be re-examined for competence again at a later date.

If he finds that Murphy is competent, trial proceedings could begin.

Murphy has been in the state’s custody since the charges were announced in 2012.

On the night of Brooklyn’s death, Huard called 911 to report that the infant, whom she was babysitting, was not breathing. The infant’s mother, Nicole Greenaway, said police investigators told her that her daughter had died from suffocation. Traces of a medication prescribed to Murphy, then 10, were found in the baby’s system.

Matt Hongoltz-Hetling — 861-9287 [email protected] Twitter: @hh_matt