Marc Karun, 53, was arrested Wednesday by Maine State Police on a fugitive from justice warrant out of Norwalk, Connecticut.
Norwalk police say he sexually assaulted and killed 11-year-old Kathleen Flynn while she was on school grounds back in 1986.
Lt. Terry Blake of the Norwalk Police Department said Karun faces murder and kidnapping charges.
“This is the culmination of a lot of hard work and the dogged pursuit by Lt. [Art] Weisgerber on this particular case,” Blake said. "And ultimately the arrest of Marc Karun will bring justice, hopefully, to the family."
He said Flynn was last seen alive on Sept. 23, 1986 leaving her middle school on a walking path that leads to her nearby home.
According to the department's Facebook posts about the unsolved homicide, she was strangled to death.
The Flynn family issued a statement Thursday thanking the police department for their work, and added, "this continues to be a difficult time for us."
Karun is a lifetime registrant on the Maine Sex Offender Registry for a 1989 conviction in Connecticut that sent him to prison for six years. One of his Stetson neighbors and a town official said he lives in a home that was purchased in 2013 by a family trust and he doesn't appear to work.
His neighbor described him as unusual.
“He was a person that was very interesting because he would stand out by his driveway and point fingers at you, or salute you – things that were not common for people to do,” the man said.
Karun has a bail hearing at the Penobscot Judicial Center in Bangor on Friday afternoon. Blake said more information about the two charges will be released then.