A mother and one of her teenage identical twin daughters were allegedly killed by an elderly man during a petty neighborhood dispute. 

Jessica Lashly, 38, and Jersey Greer, 17, were shot in the head outside their House Springs, Missouri, home on Saturday night, the Jefferson County Sheriff's Office said.

Robert Winkelman, 73, walked to Lashly's home and ambushed her with questions about alleged activities at the home, according to police.

The mother of two made a comment that Winkelman seemingly did not like, as he then pulled out his weapon and fired at her, the preliminary investigation found.

Greer rushed to help her mother, but Winkelman allegedly shot her too.

Police said the elderly man chased a third person, who was not named, while he was armed, but that individual was not injured.

Winkelman turned the gun on himself outside his own home as deputies tried to confront him, police said.

Lashly and Greer were taken to the nearby Mercy Hospital South in critical condition. Both died Monday after their family took them off life support.

Winkelman has been charged with two counts of first-degree assault and two counts of armed criminal action. He remains hospitalized in critical condition. 

Preliminary investigation revealed that Winkelman had 'ongoing frustrations' with activities occurring at Lashly's residence.

Authorities have not disclosed what activities allegedly upset him, but one neighbor told the St Louis Post-Dispatch that Winkelman did not approve of how Lashly and her family maintained the property.

Greer's twin sister, Justice, was at work at the time of the deadly attack, her aunt Sara Lashly told the newspaper.

Sara said the twins and their mother 'were always together,' noting that her heart now breaks for the surviving teenager.

'That poor baby,' she said of Justice. 'She just lost her whole world right there.' 

A GoFundMe has been established to help Justice and her family with medical bills and funeral expenses. 

Lashly worked for her family's tree-cutting business, which services homes across greater Jefferson County.

She was a seemingly dedicated mother, describing herself in her Instagram bio as the 'proud mother of Justice Ann & Jersey Lynn.'

Both twins attended Northwest High School in nearby Cedar Hill and played on the women's lacrosse team. 

'She was very sweet, easy to talk to,' Sara said of Greer. 'She was getting ready to go into her senior year. She worked hard, played sports. I don't know how she had the time to do everything.' 

Another aunt, Christina Greer, hailed Greer's final act of kindness.

'Even in the last moments, she knew that she had to protect others, and that's just what she does,' Christina told KPLR. 

Lindsay Palmer, who is associated with the school's lacrosse program, said she is 'absolutely shattered' by the loss of Greer and Lashly. 

'There are simply no words that make any of this make sense,' Palmer wrote on Facebook.

'Jersey girl… the joy, laughter, and light you brought into my life were truly unmatched. I've never met anyone quite like you. You had a way of making everyone around you smile, and your presence was something so special.'

The team honored the teen by giving her family a lacrosse stick covered with signatures from her teammates. 

They also flooded the hospital halls while Lashly and Greer were on life support, and were the driving force behind the crowdfunding campaign – which has already amassed more than $37,000 in donations. 

The twins' uncle, Victor Greer, also paid tribute to his niece and sister before publicly condemning Winkelman for his alleged senseless act of violence.

'Rest in paradise, my sweet Jersey girl and sister Jess,' he wrote. Until we meet again. I will love you both forever.'

In a separate post, Victor added: 'F*** YOU! Robert Winkelman, you low-life piece of s*** scum. I hope you rot in prison until you die.'

He blasted Winkelman for allegedly taking away his 'little sweet innocent niece' and vowed that the 73-year-old would soon 'get yours, you didn't escape from what you have done.'

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