Father in Riley murder case described as bipolar

Defense attorney John Darrell said Riley's wife, Carolyn - who was convicted last month in a separate trial of second-degree murder in the child's death -- was the parent who administered these drugs to the girl based on doctor's orders. He said Michael Riley's involvement with the drugs was limited largely to driving the family to medical appointments and applying for Social Security disability benefits on behalf of the family.

''Surely Michael Riley did not give that child pills,'' Darrell said.

Prosecutor Frank Middleton, however, portrayed the father as a sinister, violent figure in the family who was continually verbally and physically abusive to all the children. He said Michael Riley, in the weeks before Rebecca died, continually ordered his wife to give the sedating medications to the children so he could get peace and quiet in the home. Sometimes, he said, the children were medicated so they would fall asleep as early as 5 p.m.

He said the 37-year-old defendant was the mastermind behind a scheme to get all three children diagnosed with mental disorders so they would qualify for Social Security disability payments. The family’s sole income, Middleton said, was about $2,000 a month in federal disability payments.

''That is what’s driving the train – it's all about money,'' the prosecutor said.

Carolyn Riley is serving a life sentence, with the possibility of parole after 15 years, for her conviction, which occurred on Feb. 9 in the same courtroom as her husband's trial. Her defense was largely that she followed Dr. Kifuji's orders and that Rebecca died of an aggressive pneumonia, not an overdose of clonidine, one of the three drugs that the girl was taking.

The father's attorney, Darrell, said today that he has not made a decision about whether to put Michael Riley on the stand. It is unlikely, however, that the father would take the stand because of his past criminal record.

Riley only recently completed a two-year prison term for showing pornography to Rebecca's 13-year-old half-sister during a 2005 visit to the family's home.

As with Carolyn's trial, this case before Superior Court Judge Charles Hely is expected to last at least several weeks, including more than 30 witnesses. She also faced first-degree murder charges, but the jury chose to convict of second-degree murder.

Patricia Wen can be reached at wen@globe.com.