A 40-year-old loner who authorities believe killed six relatives in Algona, Iowa, before turning the gun on himself may have been enraged by the holiday attention showered on his sister and her three children, a family friend said yesterday.

"Here he was living with his parents, kind of being the center of attention all the time, and then Marilyn and the kids came home," said state Sen. Berl Priebe, a close friend of John and Agnes Dreesman. "Who knows, but that might have pushed Robert over the edge."

Authorities believe the Dreesmans were killed by their son Robert.

John Dreesman, 79; his wife, Agnes, 74; Robert; the Dreesmans' daughter, Marilyn Chuang, 48, and her three children, Jason, 12, Jennifer, 11, and Joshua, 8, were found shot to death at the Dreesman home Wednesday.

Authorities said they had some indication Robert Dreesman had undergone counseling for mental problems, and said they found two weapons in the home.

"I would say this whole incident occurred in a matter of 15 to 30 seconds," said Ron Makin, a Division of Criminal Investigation agent in charge of the probe of the slayings in the north-central Iowa community.

"The evidence we found at the scene indicates he did the shooting and he died of a self-inflicted gunshot wound," Makin said.

In New Hampshire yesterday, a man with a history of drug charges killed three men and critically wounded two others in the towns of Nashua and Londonderry. Rafael Rodriguez, 38, of Nashua, shot at a policeman trying to arrest him as a suspect in the killings, and was killed by the officer, police said.

Police said Rodriguez entered an apartment building in Nashua and killed Richard Proulx, 41, of Lawrence, Mass., then went outside and shot Jose Soto, 20, of Nashua, who was listed in critical condition at a Nashua hospital.

Authorities said Rodriguez drove to Woodmont Orchard in Londonderry and shot Nicanor Rodriguez, 59, and Julio Otero Rivera, 32, both of Londonderry. Nicanor Rodriguez, a distant relative, died; Otero Rivera was in critical but stable condition today at a hospital in Derry, N.H..

The officers said the gunman then drove back to Nashua and fatally shot Jesus Santos, 22, of Nashua, in the doorway of an apartment building.

In Dayton, Tex., 17-year-old Edward Lee Rouse Jr. was accused of killing his mother, Rita Porter, 38, and a 9-year-old stepbrother, Matthew J. Porter; injuring his stepfather, Larry Porter, 37, and setting fire to their house early Wednesday. Preliminary autopsy results indicated that Matthew Porter died of stab wounds to his back and that his mother was killed by shotgun blasts to the throat and chest.

A cousin in Baytown, Tex., where Rouse drove after taking a neighbor's car and where he was arrested, said he told her family that "it started after a little argument about picking up toys."