BARNSTABLE - Erin Colleran killed her daughter on impulse while in a profound depression, according to two mental health experts who testified yesterday in Barnstable Superior Court.

One of those experts, Dr. Charlotte Denton, a forensic psychologist, evaluated Colleran, 29, at Taunton State Hospital shortly after the Sandwich woman was charged with killing her daughter.

The other, Dr. Martin Kelly, a forensic psychiatrist testified for the defense yesterday, but on at least a dozen other occasions has appeared as a prosecution witness in Barnstable County courts. In this case he was hired by the defense to evaluate Colleran's mental and emotional state before trial.

Colleran, a Sandwich resident, confessed to both Sandwich and state police that she smothered then strangled Skyler Morse, 21/2, on Dec. 18, 2001, while the toddler's father slept in a nearby bedroom.

Prosecutor Brian Glenny hopes to persuade the jury that Colleran is guilty of first-degree murder, killing her daughter deliberately and with extreme cruelty. If convicted of this, Colleran would be automatically sentenced to life in prison without possibility of parole.

Defense attorney Drew Segadelli hopes the jury will find his client not guilty by reason of insanity.

Insanity definition

If this is the verdict, Colleran would be sent to a state psychiatric facility until a panel of mental health experts deemed her ready, if ever, to resume life outside the facility.

In order to get that verdict, Segadelli must persuade the jury of 10 women and four men - two will be randomly selected as alternates before deliberations begin - that his client is insane, according to the requirements of the law.

The legal definition of insanity may differ from the common perception of insanity, according to some of the mental health experts who testified yesterday.

Kelly told jurors that Colleran was in the midst of a psychotic depression at the time she killed her daughter.

According to Denton, Colleran contemplated suicide in the week before her daughter's death. Colleran was losing weight, not sleeping and was extremely anxious. Although she had been treated for anxiety and depression in 1997, in the weeks prior to her daughter's death, Colleran did not tell anyone she was depressed, Denton said.

Nor did she tell anyone that she was thinking about suicide, according to Denton.

On the morning she killed Skyler, Colleran contemplated an overdose, but the only pills in the house were Tylenol. She stood in the kitchen with a knife against her wrists but could not cut her skin, Denton said.

"She couldn't kill her self. She wanted someone else to do it," Denton said.

Psychologist's testimony

Colleran told Denton that shortly after laying down the knife, she took Skyler into the living room where the little girl finished a bottle, then laid her face against her mother's shoulder and fell asleep.

Colleran said she placed her sleeping daughter on the couch and pushed her face into the cushions, first with one hand and then two as the little girl cried out and flailed her feet in a struggle to breathe.

When Skyler stopped moving, Colleran flipped her over and noticed the little girl's lips had turned blue. Fearing that if Skyler survived she would be brain damaged, Colleran decided to "finish the job," Denton said.

In earlier testimony a forensic pathologist said who ever strangled Skyler squeezed hard enough to leave fingernail imprints on the child's flesh.

According to Denton, Colleran said she could not explain why she killed her daughter. "I kept doing it. I couldn't stop. It was like I was possessed," she told the psychologist.

However, in response to a question, Colleran admitted that had someone else been present in the room, she probably would not have tried to kill Skyler, Denton testified.

Closing arguments are scheduled to begin at 10 a.m. today in Barnstable Superior Court.

(Published: June 19, 2003