NEW BEDFORD – The teenager suspected of attacking three men at a gay bar and killing an Arkansas police officer and a female companion left a note indicating he planned “something violent,” authorities said Monday.

Jacob D. Robida, 18, was fatally wounded when he opened fire on officers at a roadblock following a high-speed chase through the Arkansas hills Saturday. He was shot twice in the head and died at a hospital the following day.

In New Bedford, where police say Robida attacked patrons at Puzzles Lounge with a hatchet early Thursday and then opened fire with a handgun, detectives found what they considered a troubling message in Robida’s room, Bristol County District Attorney Paul Walsh Jr. said Monday.

“We didn’t interpret it necessarily as a suicide note, but it was certainly the note of a desperate man who had some plans to continue doing something violent,” Walsh said.

The content of the note was not released.

Robida’s mother told police her son had come home after the attack around 1 a.m. with his head bleeding. Police found a sock and paper towels with brownish-red substances on it. It was unclear whether he left the note before or after the attack.

In addition to the message, police found an apparently homemade poster with a Nazi swastika and anti-Semitic writings, as well as a makeshift coffin, Walsh said. He said the significance of the coffin isn’t known.

A police report released Monday said investigators also found weapons, including 85 rounds of ammunition, a Samurai sword, one knife and two knife sheaths in Robida’s room. A knife without a sheath was found outside of Puzzles.

They also found two bumper stickers in Robida’s room, which read: “I dress this way to scare your kids” and “My day is not complete until I’ve terrified a complete stranger,” the report said.

Police were trying to determine whether Robida had any accomplices in New Bedford or elsewhere, though evidence suggests he acted alone, Walsh said.

After the New Bedford attack, which police labeled a hate crime, Robida surfaced Saturday in Arkansas, where he killed Gassville police officer Jim Sell at a traffic stop, setting off a 20-mile chase that ended in a gun battle when Robida allegedly shot and killed his passenger, 33-year-old Jennifer Rena Bailey.

Robida lived in West Virginia with Bailey, a mother of three boys, from sometime in 2004 to February 2005, West Virginia State Police Sgt. C.J. Ellyson said Monday.

Three of Robida’s friends from a home page the teen created on the Web site MySpace.com told The Associated Press that Bailey was Robida’s ex-girlfriend. Police said they were checking e-mails and Internet correspondence between the two and had seized Bailey’s computer.

“We’re trying to trace down their steps and find out when they hooked up, if she invited him over willingly or if she was abducted. We’re trying to answer the unanswered questions,” Ellyson said.

“Her mother was aware of the relationship between them. The mother was under the impression the daughter had ended the relationship,” he said.

Autopsies of Robida, Bailey and Sell were expected to be completed Monday and the results would be given to investigators, J.R. Howard, director of the Arkansas State Crime Lab, said.

Walsh said he has sent four investigators to assist authorities in Arkansas and two more to West Virginia to assist in the investigation.

Police in Massachusetts are also trying to determine where Robida got his handgun, a Ruger firearm. In Massachusetts, handgun owners must be at least 21 years old.

Walsh said he feared Robida’s arrest could have been even bloodier, particularly if he had been confronted in a public place. New Bedford authorities had issued public warnings that they considered Robida armed, dangerous and possible suicidal.

“I really thought he was going to take five or six people with him,” Walsh said. “My fear was that he’d shoot up the works.”