(CNN) -- The convicted rapist arrested last week in Gorham, Maine, after 34 years on the lam was a quiet, laid-back, hardworking, sweet young man whose lurch into violent behavior in his last year of high school remains a puzzle, according to a childhood friend.
In the winter of 1976, when Doris Dickson was nearly 12 years old, her family moved into a modest two-story house on Myrtle Street in Rockland, Massachusetts, a half hour south of Boston, she told CNN.
The next spring, the Irving family bought the house next door, she said. Her new neighbors were Gary, who was then 16, his 11-year-old brother, Gregg, and their parents, Carl and Margaret.
Soon thereafter, Gary befriended his younger neighbor, a slim redhead with bangs, braces and glasses.
The blond, 6-foot Irving enrolled in Rockland High School, where he got good grades even as he held a part-time job at a supermarket, played trombone in the school band, listened to disco on a sound system he set up -- complete with strobe lights -- in his attic and made plans to go to college, said Dickson.
That promising high school student became the 52-year-old fugitive arrested last week in southern Maine, accused of skipping bail after his conviction in the rapes of three women in Massachusetts in 1978.
Despite the four-year age difference, "we were very close friends -- too young to be boyfriend and girlfriend, but spent that amount of time together," Dickson recalled in a telephone interview.
They listened to K.C. and the Sunshine Band's "That's the Way I Like It" and became close, she said. Although the relationship did not include sex, it did include "probably more than should have gone on between a 13-year-old and a 17-year-old."
But the friendship ended abruptly in the spring of 1978. "He all of a sudden got a very violent thing going," Dickson said. "Gregg told me Gary had gone after his mother with a knife."
Dickson said she confronted Irving, who did not deny the account. "He was angry," she said. "All of a sudden he was one angry teenager."
That was enough for Dickson to end the friendship. "I told him, 'Get away from me, I don't want to talk to you any more.'"
Gregg Irving did not return a call from CNN, nor did his mother, Margaret Irving.
That night or the next morning, Gary Irving drove his mother's car through his family's garage door, Dickson said. "Whether he was mad at me or her, I don't know. I didn't talk to him again."
That summer, Dickson's mother showed her an article in the local newspaper about Irving. "Do you know what rape is?" she asked her daughter.
Irving was being tried on three separate counts of rape with force, unnatural acts and kidnapping. In one case, he was accused of knocking a victim from her bike and taking her to a secluded area, where he raped her repeatedly. In another, he was accused of raping a woman after threatening her with a knife.
During the trial, Dickson saw him one last time. "I was with my sister; he was with Gregg," she recalled. "We were walking in opposite directions, and my sister and I crossed the street to avoid him." No one said anything.
Soon after, a 12-member jury in Norfolk Superior Court found Irving guilty on the counts. The judge -- new to the job -- offered him a weekend to put his affairs in order before reporting to jail.
Instead, Irving, facing a possible sentence of life in prison, fled and landed on Massachusetts' most-wanted list.
His parents, whose family now included a younger son with Down syndrome, were struggling, Dickson said. They moved out of the house on Myrtle Street, and it was left vacant for months, then sold.
In the years since, Dickson said, she has never figured out what caused Irving to change. "Some time in there, he lost it. Something happened. He was not like that."
Now 48 and working as a technical writer, a reporter for a local paper and the owner of a pet supply shop, Dickson said she has never forgotten her former neighbor.
"I've expected him to jump out around a corner," she said.
In February 2012, after the arrest of alleged mobster James "Whitey" Bulger after 16 years on the run, members of the Massachusetts state police's fugitive task force and the FBI met with Dickson to see whether Irving, too, could be located.
"They were trying to develop a picture of who this was back then in order to figure out where he would have been drawn."
It turns out he had been drawn just 129 miles north, to Gorham, Maine.
That's where, on Wednesday night, police and the FBI arrested Irving as he, his wife and their grandchild were watching television.
"He requested to know how we found him," Maine State Police Sgt. Robert Burke told reporters.
Burke would not divulge what led authorities to Irving. On the front of the house on South Street, a sign reads "Irving." Police said Gary Irving had been living as Gregg Irving, the name of his younger brother. Records show he had lived there since 2002 and perhaps since the mid-1980s, police said.
Confirmation of his identity was made via a scar on his chest from heart surgery he underwent as a child and a fingerprint match, police said.
Investigators found guns in the house, police said. As a felon, Irving was not allowed to possess the guns, and he will be charged by federal authorities on firearms offenses, Massachusetts State Police spokesman Dave Procopio said.
When he showed up in court on Friday, dressed in a yellow jumpsuit with his wrists cuffed in front of him, Gary Irving looked little like his Most Wanted poster, which showed 1978 a picture of him clean-shaven.
In court, his hair was tied into a ponytail, his beard was bushy, and both were flecked with gray.
But one thing had not changed. "I'd know those eyes anywhere," Dickson said after looking at television accounts of her former friend. "Those are the eyes."
He was taken to Cumberland County Jail in Portland as a fugitive from justice, this time without bail.
"I can tell you that his wife appeared like she was in a state of shock," Burke said.
Neighbors in Gorham, a town of 16,000 residents, also expressed shock that the house with the swing set outside had been home for years to one of Massachusetts' most-wanted fugitives.
"Everybody's quite amazed at what took place here," said Keith Meggison, who has lived for 28 years on South Street, four houses down and across the street from the Irvings. "It was kinda strange that nobody picked up on this."
The Irvings apparently did take pains to keep out of the public eye. "Their windows were always closed; they always had sheets over their windows," said neighbor Alyssa Lurvey. "They kept to themselves so much that we never saw them, we never knew who they were."
"He was always pleasant and nice," neighbor Patricia Dixon said. "You never know who's living next door, I guess."
"We really are just starting to understand and know who this guy is," Maine State Police Lt. Walter Grzyb said. "They're going to want to know everything about him that has happened since 1978."
Police said they are planning to see whether they can link Irving to any unsolved rapes in the area. His house, on a main street into town, is about a quarter-mile away from three public schools and less than a mile from the University of Southern Maine. Some 60% of the 1,200 students who live on campus are women, a school spokesman said.
Dickson said she plans to visit her former friend in prison to ask him about his transformation 34 years ago: "What happened to you? What were you thinking? How did you get so angry?" she said she will ask.