Online Registry Or Target List?

In Maine, police said they had no idea why Marshall selected the 34 offenders he checked on, or why he chose Elliott and Gray from that group. Both men lived hours from Houlton, Maine, the town near the U.S.-Canada border where Marshall was staying with his father.

"They may have been the only ones he could find," said Sgt. Stephen Pickering, a criminal investigator with the Maine State Police. He said police found the other 32 offenders safe.

Though the two victims were listed on the same registry, they had committed different crimes. Gray, 57, was convicted of the rape of a child. He assaulted the youngster over a period of three years, beginning when the child was 7, according to prosecutors. Elliott, 24, was convicted of sexually abusing a minor, which apparently stemmed from having sex with his teenage girlfriend, according to police.

Police said that Gray was sleeping on the couch in his home in Milo, Maine, about 3 a.m. Sunday when his dogs started barking outside. Gray's wife roused him, saying she had seen a man in a dark jacket outside, but then the man opened fire through the window, killing Gray, police said.

About five hours later and 24 miles away, Elliott was shot after answering the door at his trailer home in the town of Corinth. Police said his girlfriend noted the license plate on the gunman's pickup, which belonged to Marshall's father.

The trail eventually led investigators to the Bangor, Maine, bus station and to a 1:45 p.m. Vermont Transit Lines bus bound for Boston. Police pulled it over just minutes from its destination, and asked the driver to turn on the overhead lights.

Marshall fatally shot himself seconds later, authorities said.

Police found a laptop computer in his backpack, and were hoping it might yield clues about his motive. In the meantime, the murder left Elliott's father, 61-year-old Wayne Elliott, wondering why his son, whom he called "my best friend," was chosen.

"Just picked him randomly, I believe now," Elliott said in a telephone interview. "He didn't know a thing about my son."