A former Baltimore County teacher was sentenced Tuesday to life in prison without parole for murdering her estranged husband, despite a defense plea that she receive a lenient sentence because of her psychological problems.

Mary C. Koontz, 60, her right arm shaking slightly, said nothing when the sentence was pronounced, her expression as empty as it had been for most of an 11-day trial that ended last month. She was convicted of killing Ronald G. Koontz, a former Towson High wrestling coach and county schools administrator who was shot four times on June 19, 2009, and of the attempted murder of their teenage daughter.

But shortly before Baltimore County Circuit Judge Thomas J. Bollinger issued her sentence, Koontz turned to face the girl she once tried to kill.

"I want you to know I am so very sorry," she said, looking directly at 17-year-old Kelsey, the youngest of her three children, in the Towson courtroom. "You deserve nothing but goodness in your life."

Then, as the defendant, her ankles shackled, sat down to hear her sentence pronounced, Kelsey raised her hand and gave her a little goodbye wave.

In addition to the sentence on the first-degree murder charge, Koontz, a former English teacher at Sparrows Point High School, was given a second life term for the attempted murder of Kelsey, and 20 years each on two weapons charges. Those sentences will run concurrently with the term in the murder count.

Bollinger agreed to the defense's request that he recommend Koontz be evaluated for admission to the Patuxent Institution, a maximum-security correctional facility in Jessup that focuses on providing psychotherapeutic treatment for violent offenders.

The jury in her trial rejected the defense's contention that Koontz was insane and suffering from so-called dissociative disorders and therefore did not understand the gravity of her actions.

Nevertheless, her lawyer, Richard M. Karceski, asked the judge Tuesday to consider Koontz's long history of emotional fragility when deciding her sentence. "It was real, it was there, and it contributed to Mrs. Koontz's actions," he said. "Mrs. Koontz's ticket to her destination began long ago, since she was a child."

Karceski said his client's disorders remained untreated for years and "began to fester and grow worse." The final straw came when, her marriage in disarray, she was ejected from the family's home in November 2007, he said. Forced into an uneasy exile in a condominium on Marco Island, Fla., Koontz called her husband and daughter as many as 30 times a day, often delivering obscenity-laden harangues, many of which were played for the jury.

Ron Koontz's actions in separating himself from his wife of two decades, Karceski said, had "created a chasm" and caused her disorders to worsen.

"He could have handled it differently," the lawyer said. "He perhaps didn't realize the gravity of the situation. Mary Koontz became more broken and less rational in her isolation."

Arrested in the killing of her husband — whom she ambushed after sneaking into the house they had shared in Glen Arm with a key she had kept — Koontz told a doctor that she "couldn't take it anymore," her lawyer told the judge.

Karceski conceded that, no matter how rejected his client might have felt, "you don't go out and commit murder, and shoot at your daughter and try to kill her."

In the courtroom's front row, Kelsey and her half brother, Joby Luca — Mary Koontz's son by an earlier marriage — turned away from Karceski as he sought to explain to them that, for legal reasons, their mother had been unable to apologize during the trial. At that point, Deputy State's Attorney Robin S. Coffin, who prosecuted the case, asked the judge to prevent Karceski from addressing the defendant's children, but Bollinger dismissed her objection.

Karceski continued by insisting that his client was very remorseful for what she had done, and bore no malice toward anyone.

"She does not blame," Karceski said. "She does not despise."

In her own remarks to the judge, Kelsey, reading from a prepared statement, said her heart had been "completely broken" by the death of her 67-year-old father. She described him "blubbering like a baby" when she passed her driving test, doing a back flip off the diving board into their pool as the first jump every summer, wrapping batteries in Christmas paper with a "little clue" as to what might be inside.

"I still have my dad's number saved in my phone," Kelsey said. "Only his name has changed from 'Dad' to 'Dad-I-miss-you.' I know this is silly, but sometimes, when I'm really missing him, I'll press 'send' just to hear the sound of the ring. I feel like maybe, by some miracle, he just might answer."

Outside the courthouse after the hearing, Kelsey, who will soon begin her first semester at an out-of-state college, told reporters that she was excited to "move on with my life" and put her mother's trial behind her. She said it had been "really empowering for me to be able to speak my mind" in the courtroom.

She added that she was comforted by the notion that her mother is unlikely to ever be free. The alternative, she said, was "scary." Asked about her mother's apology, Kelsey said she had been unimpressed.

"I've lived with her and I know how she is," Kelsey said. "Bad things can happen to people, but I'm not going to get down about it and ruin other people's lives."

She said that her mother had neglected her responsibility to seek help for herself. "It's possible," Kelsey said, "to make sure you come out on top and be a better person."

nick.madigan@baltsun.com