A teenage rape victim and her father lambasted 19-year-old Owen DeCosta on Tuesday as he was sentenced to seven years in prison for sexually assaulting the victim over a prolonged period and for his role in an unrelated Groton home invasion.

DeCosta of New London had pleaded guilty in New London Superior Court to risk of injury to a minor and first-degree burglary.

Judge Hillary B. Strackbein sentenced him to 20 years in prison, suspended after seven years served, followed by 10 years of strict probation under a plea deal worked out by prosecutor Theresa Anne Ferryman and defense attorney Matthew G. Berger.

The victim had disclosed in March 2015 that DeCosta, whom she knew, had sexually assaulted her beginning when she was 8 years old until she was 13.

DeCosta, charged that same month by Groton Town Police with taking part in the armed home invasion of a marijuana dealer on Crystal Road, has been incarcerated at the Manson Youth Institution while his cases were pending.

On Tuesday, the victim sat a few feet from him in the well of the courtroom, flanked by her mother and Victim Advocate Beth Ann Hess while reading a lengthy victim impact statement.

She said she suffered anxiety, depression, panic attacks, post-traumatic stress disorder and suicidal feelings because of the incidents, noting that before, "I was just a normal kid."

She said it became a battle just to get out of bed, but that she is starting to get back her life.

"I thought I was the crazy one, I was the monster," she said.

Her father cursed at DeCosta and said he should be serving 70 years in prison, not seven.

"As a parent, this is the worst fear you have, having something awful like this happen to your daughter," he said.

Berger said DeCosta also was a child, ages 11 to 16, when the crimes occurred. He said the adolescent brain is not fully formed and children lack impulse control. He said DeCosta was not well supervised as a child and that the word "feral" was used to describe his upbringing in a presentencing investigation.

"I don't think we should throw people away for things they did as children," Berger said.

The judge said the sentence takes into account DeCosta's age as well as the seriousness of the crimes.

"I don't know if you understand the pain you caused," Strackbein told DeCosta.

The judge told the victim her life does not have to be defined by the crimes.

DeCosta, who had stood silently between his mother and his attorney during the lengthy and emotional hearing, said, "You won't see me after my sentence is complete."

He is required to register as a sex offender with the Department of Public Safety for 10 years upon his release from prison and will be prohibited from contact with minors.

He is prohibited from ever having contact with the victim under a standing criminal protection order that does not expire until 2099.

k.florin@theday.com