LEESPORT, Pa. - About three weeks before she and her three young children were killed at gunpoint on the floor of their living room, Megan Swingle Short had called 911 to say she was afraid of the man who would end up murdering her family - her husband.

She told a Berks County emergency dispatcher that she and Mark Short had been arguing. But Mark Short was gone from the family's house in Sinking Spring when police arrived on that day in July.

Officers told the 33-year-old mother how to get a protection-from-abuse order to keep him away.

"She said she was going to get one the next day," Sinking Spring Police Chief Lee Schweyer said Monday. "But she never followed through."

Instead, investigators say, Mark Short, 40, took matters into his own hands, setting in motion a final few weeks that ended in slaughter. With his marriage and job collapsing, he bought ammunition and a five-shot, .38-caliber handgun.

Two weeks later, he took the kids to Hersheypark. The next afternoon, on Aug. 6 - the day his wife planned to move with the children to Bucks County - Short gathered them in their living room. He fatally shot her and their 8-year-old daughter, Liana; 5-year-old son, Mark; and 2-year-old daughter, Willow, who had been dubbed a miracle after surviving a heart transplant as a newborn.

Short also killed the family dog. He reloaded the gun, wrote a suicide note admitting the crime, and squeezed a final shot into his head.

"This was a very, very unfortunate incident," Berks County District Attorney John T. Adams said at a news conference to describe the investigation. "I don't know that anything can be learned other than, when leaving an abusive relationship, it's often a very dangerous time for a victim."

Besides the 911 call, police said, they found no records in their files of domestic discord at the house on a corner of Winding Brook Drive.

Investigators said their conclusion was anchored by forensics: an autopsy of Mark Short, his fingerprint on a live bullet round, and handwriting on the suicide note they said matched his. Toxicology results, which could reveal whether alcohol or drugs were in his bloodstream, were pending, Chief County Detective Michael J. Gombar said.

Authorities revealed few details about the scene of the slayings, except to say that the children and their mother were on the living room floor with blankets and pillows. They also declined, at the request of Megan Short's family, to release the contents of the suicide note.

There had been signs of building tumult for the couple. Adams said investigators determined that earlier this summer, the Shorts were involved in such a heated dispute while staying at a Philadelphia hotel that hotel security got involved.

But Philadelphia police were not notified, he said.

Asked if Sinking Spring police might have done anything differently after responding to Megan Short's July 18 call to 911, Adams said officers followed protocol.

"The Police Department did everything that they are legally able to do in that situation," Adams said. "They provided information to Megan Short to give her the ability and the instructions on how to obtain a protection-from-abuse order. They did everything correct."

Had she sought an order, police would have had the authority to find and confiscate the gun her husband legally bought the next day in Lancaster County, the police chief said after the news conference.

"The PFA gives us rights to take the firearm off of him," Schweyer said.

In online comments, Megan Short shared signs of her marital discord and her plan to leave her husband. On July 25, investigators learned, she leased an apartment in Yardley, much closer to her roots in Northeast Philadelphia, where her mother lives.

At the same time, her husband was having problems at work. On Aug. 1, police say, Mark Short was demoted at his real estate-related job because of absences. That Friday, he took his kids to the amusement park.

The next day, he was supposed to rent the moving van that would carry them to their new home. Megan's mother, Jacquelyn Massott Campbell, and other family members were waiting for her at the new apartment, Adams said.

Her failure to show up led to a series of frantic calls by relatives to Sinking Spring police. Officers broke into the house and found the carnage.

Adams on Monday echoed what domestic-abuse advocates say is critical for women who find themselves in fear for their lives: Reach out for help by calling an abuse shelter or contacting police.

"We urge anyone who's in a similar situation to develop a safety plan and contact their local domestic violence agency for assistance," he said.