HOULTON, Maine — A tearful Thayne Ormsby told police how he repeatedly stabbed two men and a 10-year-old boy nearly two years ago in Amity.

“I didn’t try to be fancy, I wanted to be quick,” Ormsby said in a videotaped interview with Maine State Police detectives. “Somewhere in the subconscious of my mind, I developed myself as an assassin.”

Ormsby’s confession was played Thursday morning for the jury during his trial on murder and arson charges in Aroostook County Superior Court. Several members of the victims’ families left the courtroom as the defendant described the stabbings.

Jurors appeared to be paying close attention to Ormsby’s confession. Ormsby, dressed in the same gray suit he has worn since jury selection began last week, took copious notes as the video played on a small screen at the defense table.

Ormsby, 21, has pleaded not guilty and not guilty by reason of insanity to three counts of murder and an arson charge in connection with the stabbing deaths of Jeffrey Ryan, 55, Ryan’s son Jesse, 10, and Ryan family friend Jason Dehahn, 30, all of Amity, on June 22, 2010. They were found dead about 27 hours after the killings at the Ryans’ home on U.S. Route 1, according to police.

The videotaped interview in which Ormsby confessed was made on July 2, 2010, at the police station in Dover, N.H. Jurors heard about 40 minutes of it before court was recessed Wednesday, but the tape was stopped just as Ormsby told detectives he would tell them what they wanted to know.

The defendant was arrested the same day after being interviewed by Maine State Police Detectives Dale Keegan and Adam Stoutamyer.

Ormsby told detectives that he had planned for a few days before the slayings to kill Jeffrey Ryan and Alvin Silsby, even though he had never met him and did not know where Silsby lived. Ormsby said that Ryan, Silsby and Ormsby’s father, whose name has not been revealed in court, all sold drugs.

“Back in the day, they were three of the biggest drug dealers in this area,” Ormsby said. “I wanted to rid the world of them.”

No evidence has been introduced at the trial to substantiate Ormsby’s claims about the three men. Bangor psychologist Diane Tennies of Bangor testified Thursday morning that she interviewed Ormsby when he was 12. She said he was abused by his mother and depressed. Tennies said there were reports when she saw Ormsby in 2003 that his mother abused alcohol and drugs.

“Even though I never met him, he’s a part of my life,” Ormsby said of Jeffrey Ryan in the videotaped interview with the detectives. “He’s the reason I’m missing parts of my life.”

Ormsby said he had planned to stab Jeffrey Ryan but killed Jesse Ryan and Dehahn to cover his tracks. He said that he stole Jeffrey Ryan’s truck and had intended to look for Silsby but pulled into a road to a junkyard next to Robert Strout’s home after a man driving a logging truck honked at him and he became scared.

The start of the trial was delayed Thursday after Superior Court Justice E. Allen Hunter, who is presiding over the trial, questioned each juror individually. He asked which of them had heard the alternate juror who was dismissed Wednesday make comments about Deputy District Attorney William Stokes, who is prosecuting the case.

Eight of the 14 remaining jurors, including the two remaining alternates, said they heard the dismissed juror express his admiration for how Stokes was handling the case. The juror was dismissed after he approached Stokes during the lunch break and asked to shake his hand. Stokes declined.

All the jurors questioned Thursday morning who had heard the comment said the incident had not influenced them and they could remain impartial.

Hunter denied a defense motion to declare a mistrial and dismiss the jury. The judge also denied a motion to sequester the jury as impractical. He has ordered that jurors remain in the jury room during lunch. They are being provided with a meal, Hunter said.

Ormsby grew up in Ellsworth and went to Ellsworth High School until he dropped out his senior year. At the time of the killings, he was living with Robert Strout Sr. and his wife, Joy Strout, 63, in Orient.

Robert Strout Sr., who has pleaded guilty to helping Ormsby destroy evidence after the slayings, is expected to testify late Thursday or early Friday.

Because of his insanity plea, Ormsby will be tried in two phases. In the first and longer phase, the jury will be asked to find whether he is guilty of the charges on which he has been indicted. If he is found guilty, the jury will hear evidence as to his state of mind at the time of the crime. Jurors then will be asked to determine whether Ormsby was criminally responsible for his actions.

If the jury finds he was insane when the crimes were committed, Ormsby would not be sent to prison but to the Riverview Psychiatric Center in Augusta for an undetermined amount of time. If jurors find him guilty and sane, Ormsby would face a sentence of between 25 years and life in prison on each of the murder charges. He would face up to 30 years in prison if convicted of arson.

Judges are allowed to impose life sentences in Maine under specific circumstances. One of them is being convicted of multiple murders.

The trial is scheduled to conclude on April 20. The court will be closed Monday for Patriot’s Day. Testimony will resume Tuesday.