ALFRED — Prosecutors on Monday called witness after witness whose cumulative testimony showed that Derek Poulin wasn’t where he said he was on the day in 2012 when his grandmother was beaten and stabbed to death and set on fire in Old Orchard Beach.

But the most surprising witness came in the morning before jurors arrived at the courthouse for the third day of Poulin’s murder trial. Poulin’s father told the judge that he would not testify against his son on constitutional grounds – namely, that he could incriminate himself by doing so.

Reginald Poulin’s declaration to Justice John O’Neil Jr. in York County Superior Court set the stage for Poulin’s attorney, Amy Fairfield, to name the father as an alternate suspect in the death of 61-year-old Patricia Noel, Poulin’s grandmother and Reginald Poulin’s mother.

Derek Poulin, 26, is accused of killing his grandmother on Oct. 23, 2012, in her Old Orchard Beach home by bludgeoning her with a wrench and golf club and stabbing her repeatedly with a knife before setting her body and her house on fire.

Police connected Poulin to his grandmother’s death by a blood-colored stain on his boot that had Noel’s DNA on it. Also, statements he made to investigators on the evening after Noel’s body was found about where he was that day did not match receipts and records police obtained later.

O’Neil called Reginald Poulin to the witness stand to answer questions outside the jury’s presence because Poulin’s attorneys had demonstrated to him that the elder Poulin’s alibi from the day of the fire also had holes in it and that the father had a financial motive from insurance for Noel’s death. Both Poulin and Reginald Poulin lived with Noel at the time.

Prosecutors said they did not contest Reginald Poulin’s intention to use his Fifth Amendment privilege not to testify on grounds that his testimony could be self-incriminating, but they also said they don’t have evidence to charge him in connection with Noel’s death.

“It’s my understanding that you intend to use the Fifth Amendment,” O’Neil said to Reginald Poulin in the courtroom.

“Yes, I do,” he responded.

With that, the judge allowed Reginald Poulin to leave the courthouse for the day, although Fairfield said she may want to call him as a defense witness after the prosecution finishes calling its witnesses.

Poulin’s mother, Cathleen Emery, testified before the jury that she continued to stand by her son “100 percent,” that the police “hounded him” and that she doesn’t believe Poulin killed his paternal grandmother.

“I’m also here for Patty (Noel), because whoever did this to her needs to be punished,” Emery said.

Emery broke down in tears at one point in her testimony as she recalled Noel as a central woman for the entire family, describing her as “amazing” and “wonderful.”

Emery said Poulin was at her apartment in Portland when he learned in a phone call with Reginald Poulin that Noel was dead, and she described her son’s reaction.

“He went white. He said, ‘Oh my God, no. Oh my God, no.’ He started to shake. He was absolutely devastated. I tried to ask him what was going on. He was in shock,” Emery said of her son.

But much of the prosecution’s case against Poulin is about timing. A neighbor who lived across the street from Noel’s house at 44 Wesley Ave. called 911 to report a fire there shortly after 2 p.m. on the day of her death. Poulin told police he last saw his grandmother sitting in the kitchen with a cup of coffee and a cigarette as he left the house around 11:30 a.m.

Poulin told police in a recorded interview played for jurors last week that he went directly to the Bureau of Motor Vehicles in Portland to get a replacement driver’s license, but a detective from the bureau, Bruce Hurley, testified that electronic records and security camera footage show that Poulin arrived at the Portland office at 2:50 p.m. and left at 3:06 p.m.

Poulin also told police that he went to Community Dental in Portland to make an appointment to have a cavity fixed in the early afternoon, but a woman who works at the clinic, Robin Forbes, testified that Poulin didn’t arrive until about 4 p.m. and that she scheduled his appointment at 4:22 p.m.

Emery testified that she saw a note in Poulin’s handwriting on her kitchen table around 2:45 p.m., when she returned home after picking up her two younger children from school. She said that led her to conclude Poulin had been at the apartment before she got home. She also testified that Poulin came back to the apartment between his trip to the motor vehicles office and the dental clinic for about 30 to 40 minutes.

Police recorded that Poulin arrived at his grandmother’s house at 5:33 p.m., more than an hour after the call with his father. Poulin told police that he was slowed by traffic.

But Kathryn Irons, who worked as a clerk at the Catholic Charities thrift store in Portland in 2012, testified that Poulin stopped in the store and made a $5 clothing purchase that day at 4:56 p.m.

Maine State Police Detective Scott Harakles testified later Monday that he and other investigators went to Emery’s home late in the night after Noel’s death to question her and retrieve Poulin’s clothes and car for testing.

Harakles said Poulin gave him a white T-shirt and khaki pants, saying he had worn them that day. But those clothes do not match the bluejeans and polo shirt he could be seen wearing in the Bureau of Motor Vehicles security footage from earlier in the day, the detective said.

Harakles is scheduled to continue testifying Tuesday morning.

Firefighters who found Noel’s burnt body inside her bedroom did not immediately notice that she had about 70 stab wounds on her upper body.

An autopsy found no evidence of soot or smoke inhalation in her throat, indicating she was dead before the fire began.

Noel died from multiple blows to the head, skull fractures and multiple stab wounds, Margaret Greenwald, who was Maine’s chief medical examiner at the time, testified last week.

Police found a golf club handle and shaft, a golf club head, a wrench and a knife with a 3-inch blade in the shower connected to the bedroom where her body was found, investigators have said.

Poulin has pleaded not guilty to charges of murder and arson. He has been held without bail since his arrest.

If convicted, he faces from 25 years to life in prison for murder and up to 30 years in prison for arson.

Scott Dolan can be contacted at 791-6304 or at:

sdolan@pressherald.com

Twitter: scottddolan