short family
Parents Mark and Megan Short were found with their three children shot dead at their home in Pennsylvania on SaturdayFacebook

A family of five, including a two-year-old girl whose life had been saved by a heart transplant, have all been found shot dead inside their Pennsylvania home in a suspected murder-suicide.

Parents Mark Short, 40, and Megan, 33, were discovered dead in the living room of their Berks County home on Saturday (6 August) alongside the bodies of their three young children Liana, eight, Mark Jr, five, and Willow aged two.

Police say they all died of gunshot wounds, with the family's dog also shot dead at the four bedroom property in Sinking Spring, about 70 miles north of Philadelphia.

Officers said a handgun was found "near one of the deceased adults" along with a hand-written suicide note.

They did not reveal who they believed was the shooter, nor the contents of the note, but said an investigation had uncovered "domestic issues" between Mark and Megan Short.

"This is an apparent tragic domestic incident," District Attorney John Adams confirmed. "Our thoughts and prayers go out to the families at this difficult time."

Police had been called to the home in Winding Brook Drive, in the prosperous Brookfield Manor development, just after 2pm after a relative Megan was supposed to meet for lunch became concerned when she failed to turn up or answer her phone.

Officers broke into the property after receiving no reply to repeated knocks on the door. They discovered the Short family's bodies in the living room upon entry.

Berks County Deputy Coroner Joel Bonilla pronounced the Shorts dead shortly after 6pm.

Police said an autopsy on Mark Short's body was scheduled for Monday but that no autopsies were planned for the remaining family members.

Mark and Megan Short had spoken publicly in both the local press in 2014 and in the New York Times in 2015 about the struggles they experienced after their youngest, Willow, was diagnosed at birth with a congenital heart defect.

She had suffered from a variation of hypoplastic left heart syndrome and received a heart transplant when she was just a week old, going on to survive for two more years.

Megan, who said she was taking medication for PTSD, had written of the difficulty coping with the stress caused raising a child with illness, and of the problems the family experienced in getting anti-rejection medication for daughter Willow.

In one blog post she wrote: "Like many moms, I have always put my family's needs ahead of my own and forgotten to make time to take care of myself. Having a child with a life-threatening illness intensified that."

Facebook messages she recently sent to a friend had also revealed she had been planning to leave her husband of 16-years, according to the Reading Eagle.

Neighbour Angie Burke said Megan had complained that it was "hard being a stay-at-home mum," and had asked her to help move out.

Burke also revealed when she posted a link on Facebook last month to an article titled, "He didn't hit me. It was still abuse," Megan had replied underneath: "It really does a number on your mental health for sure."

The article, published in the Washington Post, spoke of the author's experience of being psychologically abused by an ex-boyfriend.

On Facebook, Mark Short had shared dozens of photos of him with his wife and three children. In one picture of Megan, he wrote: "She's still the most beautiful girl that I've ever met. I'm the luckiest guy in the world to have her as my wife and the mother of my three amazing children!"

Berks County District Attorney said in a statement on Monday the investigation into their deaths was still underway.

short family
The Short family's home in Sinking Spring, Pennsylvania, where their bodies were found.Google Streetview