A victim of an armed home invasion in Groton listened from the gallery in New London Superior Court on Tuesday as the first of four teens was sentenced in connection with the March 6 incident.

Christian Cruz, 19, who drove the three other teens to the home at 139-8 Crystal Road, had pleaded guilty to accessory to first-degree burglary.

Cruz has been incarcerated since his arrest, the day after the incident, by Groton Town Police.

Judge Hillary B. Strackbein sentenced him to 15 years in prison, suspended after three years served, followed by five years’ probation.

According to court testimony and documents, Cruz, Owen DeCosta, Samson Normandin and David Preston planned for days before taking two guns from one of their homes and forcing their way into the home of two men they believed to be marijuana dealers.

The victims said DeCosta, wearing a mask and carrying a Beretta 9mm pistol, entered through the front door, pointed the pistol at one of the victims and announced it was a robbery.

DeCosta struck the man in the head and the three other occupants of the home jumped DeCosta, fearing they were going to be shot.

The police recovered the pistol and a shotgun following the incident.

The victim chose not to address the court during Cruz’s sentencing hearing.

According to prosecutor Paul J. Narducci, he had told a probation officer who interviewed him during a presentencing investigation that he felt betrayed by Cruz, who he thought was a friend, and was unhappy with the length of the sentence and had suffered emotional and mental trauma as a result of the incident.

Narducci said Cruz, who was living in a foster home at the time of the incident, had “a not very good upbringing.”

Narducci said that, given all the circumstances, the three years of incarceration seemed like an appropriate sentence and would serve the purposes of punishment, rehabilitation and deterrence.

Cruz said he was sorry for what he had done, and his attorney, Thomas Simones, said Cruz, who is “not a rough person or gang-banger,” has accepted responsibility and wants to get his life on track.

Judge Hillary B. Strackbein said Cruz had tried every drug she could think of, according to his presentencing investigation. She said she hoped the sentence would give him “the chance to be clean and to realize a lot of people who had bad childhoods don’t end up in jail.”

The three other defendants, all of whom have remained in prison while their cases were pending, will resolve their charges during upcoming court dates.

k.florin@theday.com

Twitter: @KFLORIN