Police also confirm that the slain teen, Treyjon Arsenault, wasn’t involved in the argument that led to the shooting May 25.

Gang Deng Majok, 30, of Portland is tracked down in Saco and charged in the shooting of a Scarborough teenager in May. Police plan to release details in the case Tuesday.

Authorities won’t talk about their response before a sex offender’s murderous rampage, but others warn against judging the incident by its horrific outcome.

Anthony Lord, 35, was arrested Friday after he beat a man, stole guns and a pickup truck, kidnapped a young woman and shot five people, killing two, Maine State Police said.