A grandmother killed two of her female family members before turning the gun on herself in a double murder-suicide that has rocked her quiet Pennsylvania community.

Janice Picano, 67, shot her 18-year-old granddaughter Angelina Picano in the head at her home in South Philadelphia Monday night, a preliminary police investigation revealed.

Picano also shot 55-year-old Denise Grottini in the head before killing herself, Philadelphia police told the Daily Mail.

Angelina, who was diagnosed with autism, celebrated her 18th birthday in January and was enrolled at a high school within the Philadelphia school district.

She appeared to live at the two-bedroom home with Picano, her grandfather, Rick, and Grottini, according to property records reviewed by the Daily Mail.

It is unclear exactly how Grottini, whose surname is Picano's maiden name, is related to Picano and Angelina.

The horrific act of violence has shaken the East Marconi Plaza neighborhood, with neighbors now branding the incident as unimaginable.

'I can't even imagine it. I can't even imagine it,' local resident JoAnna Schofield told WPVI. 'I'm shocked. You just don't hear about things like that in this neighborhood. It's just a very quiet, nice neighborhood.'

Police were called to the neighborhood around 5.30pm Monday after receiving reports of a shooting inside the residence.

When officers arrived at the scene, they found all three women suffering from gunshot wounds to the head.

They were declared dead by paramedics just eight minutes later. 

Investigators believe Picano shot Angelina and Grottini, before killing herself. Officials have not revealed a prospective motive for the horrific killing.

The suspected murder weapon was recovered from the scene and the shooting remains under investigation of the Philadelphia Police Department's Homicide Unit.

Picano and her husband Rick, 73, appear to have been close with their granddaughter.

The pair regularly shared photos of Angelina on their Facebook pages, commemorating her birthdays and major life milestones, as well as special holidays and events.

'Angelina is very special young woman in my life, she has overcome more then most adults,' Rick wrote in a January post marking her 18th birthday. 

Picano made a similar post hailing Angelina as her 'beautiful granddaughter.' 

They also attended her 8th grade graduation in 2022 accompanied by Grottini.

The couple were seemingly strong advocates for Angelina, with Rick just last month sharing how devastated she was after her high school's spring dance was cancelled.

'My special needs granddaughter for 1 month has been looking forward to her high school spring dance,' he wrote, sharing how Angelina had saved up her own money to pay for her admission ticket.

'My wife and I let her pick out a party dress not cheap either new shoes. and guess what 2 days prior they canceled it only 6 kids signed up, do you know how hard it is to tell your Autistic granddaughter there's not going to be any dance,' he added.

He went on to criticize the school district for not ensuring the event moved forward.

Picano was well-loved by her own children as well, with her 41-year-old daughter Joy just last month paying tribute to her on Mother's Day.

'Happy Mother’s Day to my beautiful mommy!' Joy wrote. 'I love you more then life itself! Always been my biggest cheerleader and supporter, my rock, my best friend and my everything!!!'

Joy, a mother-of-two, has not publicly commented on her daughter's death.