READING, Pa. (CBS) — Officials say a father of three took his kids to Hershey Park the day before committing murder-suicide in Berks County.

Authorities say Mark Short wrote a suicide note, admitting to buying a gun and homicide. They say he wrote the note likely after killing his wife, kids and family dog.

On August 6, officers performed a welfare check at 51 Winding Brook Drive after Megan Short failed to appear at a lunch date with her mother.

Officers forced entry through a rear window and found the five bodies and dead dog in the living room, each with a single gunshot wound.

Officials say the suicide note was found on the dining room table, in Mark’s handwriting, admitting to purchasing a gun and homicide.

The Berks County DA says Mark bought the gun from licensed dealer in Lancaster County on July 19. A few days later, they say Megan leased an apartment in Yardley.

The DA says Mark and Megan had “domestic issues,” and a few weeks before the murder-suicide, Megan had called 911 and said she was afraid of her husband after a verbal argument. They also said that the pair was in the process of separating.

Officials say in early June, security was called to a hotel room in Philadelphia for a dispute between Mark and Megan, but there was no police involvement.

Officials say law enforcement did all they legally could, and offered Megan information on getting a protection from abuse order against her husband. She said she would the following day, but she did not.

A coroner confirmed Mark died from a self-inflicted gunshot wound to the head.

Officials say he had been demoted at work as a loan officer due to poor attendance on August 1.

Stay with CBSPhilly.com for more information as it becomes available.