PORTLAND, Maine — Prosecutors in the murder trial of 72-year-old Yarmouth lobsterman Merrill Kimball called expert witnesses Friday in an effort to debunk Kimball’s claim that he shot Leon Kelley in self-defense at a North Yarmouth bee farm shop in October 2013.

Friday marked the fifth day of Kimball’s murder trial in Portland Superior Court. By the close of the session, the prosecution had completed its list of witnesses, and defense attorney Dan Lilley had begun to call his.

Lilley acknowledges Kimball fired the shots that killed Kelley, but he has argued Kimball shot the much larger Kelley in self-defense after Kimball, his wife, Karen Kimball, and her son arrived at the bee shop owned by 95-year-old Stan Brown to collect honey they say was Karen Kimball’s.

Kelley was Brown’s son-in-law.

During testimony Friday morning, Maine’s chief medical examiner, Dr. Mark Flomenbaum, said that any of the three bullets Merrill Kimball shot at Kelley on Oct. 6, 2013, could have killed him.

In a point crucial to the prosecution’s effort to raise doubts about Kimball’s self-defense argument, Flomenbaum testified that Kelley was likely falling backward as the second and third shots hit him.

Flomenbaum performed the autopsy on Kelley the day after the shooting.

The last witness for the prosecution, which has been arguing its case since Monday, Flomenbaum stood to demonstrate his findings on how the bullets hit Kelley.

Because the second bullet became lodged in Kelley’s abdomen and the third in his lung, Flomenbaum testified, “to get the upward trajectory [of the bullets], if you’re assuming the gun’s in a fixed position, the body was falling or down on the ground.”

Lilley quickly objected to what he characterized as speculation by Flomenbaum. He argued that there was no way to know the position of the shooter and no way to determine absolutely what order the bullets hit Kelley.

Earlier on Friday, forensic expert Robert Burns of the Maine State Police crime lab held the .380 Ruger semi-automatic weapon Kimball shot that day as he demonstrated loading and firing the gun. Burns also said he determined Kimball shot Kelley from at least four feet away but not more than 10 feet.

The jury also heard Kimball’s Nov. 5, 2013, testimony to the grand jury.

In that testimony, Kimball said his wife worked for Brown for about five years and the couple would take the elderly man out for dinner on occasion. He said Karen Kimball helped Brown out at first, and then “took it over as far as processing the honey and feeding the bees all winter. This past year, she had 50 hives of her own.”

“She was supposed to own the honey because she’s the one that worked it, taking it off the comb and spinning it in the processor,” he said. “It took her all year to do it.”

Members of Kelley’s family testified this week that they were increasingly concerned that she had access to his finances and had been added to his will.

Witnesses have testified that the Kimballs went to the bee shop on Oct. 6, 2013, to pick up 14 50-gallon buckets of honey, which Lilley said was worth about $5,000.

After a confrontation outside the bee shop, Merrill Kimball shot and killed Kelley that afternoon.

Grand jury testimony presented Friday also included Kimball’s claims that he backed away from Kelley and only fired when he felt he had no other recourse.

When asked whether he thought he had “overreacted,” Kimball told the grand jury, “No way. I was so scared for my safety and my life. That’s the only reason I did what I did. I thought I was going to get hurt or killed. I can’t run, so I didn’t.”

After Flomenbaum’s testimony, Justice Roland A. Cole excused the jury, and Lilley made a motion for judgment of acquittal at 2:30 p.m.

Lilley recalled testimony by the victim’s stepson and stepdaughter earlier in the week, noting that “both pretty much indicated my client didn’t have much choice.”

“It’s a tragedy, but the fact of the matter is there is not sufficient evidence for a jury to find beyond a reasonable doubt that my client is guilty,” Lilley said.

But Cole dismissed Lilley’s motion, leaving it up to the jury to determine whether Kimball was acting in self-defense when he shot Kelley.

“The issue in this case for me is, there were three shots fired, and how the jury views that — whether he was acting in self-defense in all three shots, ” Cole said. “But it’s really a jury question at this point in time.”

Lilley called his first defense witness just before 3 p.m. Friday.

Lilley questioned an osteopathic doctor about treating Karen Kimball and her son, Damon Carroll, for bruises, muscle spasms and anxiety after the incident.

As his last witness of the day, Lilley called a man who testified he was about the same height and weight as Kelley. Lilley had the man stand beside Kimball to demonstrate the difference in their sizes.

Lilley did not say Friday who he would call as witnesses on Monday, but Cole told jurors that they would likely begin deliberations some time that day.