Chilling final words Florida teen 'killer' said to her mom before 'opening fire at home' - as girl, 16, is also accused of slaying mother's younger boyfriend who made haunting final request

A teenage girl allegedly fatally shot her mother and wounded her mother's boyfriend until she ran out of bullets and stabbed him.

Julia Grace Egler, 16, was charged with two counts of first-degree murder after she admitted to killing the couple seconds after they arrived home, police said.

The alleged confessed killer then called 911 and made up a story about hiding in her room while an intruder ransacked the home and killed the couple.

Kelley McCollom, 41, and Matthew Szejnrok, 22, were found dead at the Palm Bay, Florida, home on July 6, and Julia's story quickly unraveled.

Julia eventually told detectives she murdered them because she didn't like that her mother was dating a much younger man, and was 'not vey accepting of her gender transition,' according to the arrest affidavit.

Police say Julia Grace Egler, 16, admitted to shooting dead her mother Kelley McCollom, 41, with her own gun at their home in Palm Bay, Florida

Julia also allegedly killed her mother's boyfriend Matthew Szejnrok, 22, by shooting him and then stabbing him when she ran out of bullets. At his request, police said she then shot him in the head

Authorities said she explained that she stole her mother's gun and waited in the kitchen with it and a knife hidden in her pockets for them to arrive home about 10:30 pm.

'Welcome home,' she told them, before she allegedly opened fire on her mother with the .38 caliber revolver, shooting her several times until she was dead.

Police say Julia then turned the gun on Szejnrok as he fled to the bathroom and begged for his life, but she repeatedly shot him anyway.

When the gun ran out of bullets, she allegedly took out the kitchen knife and began viciously stabbing him on the bathroom floor.

Szejnrok, mortally wounded and in agony, 'essentially asked [Julia] to take him out of his misery', the affidavit read.

Julia walked back to her mother's room, loaded another bullet into the revolver, and shot him in the head to finish him off, police said.

She then allegedly staged the crime scene to look like a home invasion, and called 911 at 12:06 am hysterically crying that her mother had been murdered.

 'Welcome home,' she told them, before she allegedly opened fire on her mother with the .38 caliber revolver, shooting her several times until she was dead

Julia told police when they arrived that the intruder broke in through the back sliding glass door and she hid inside her room with her pet pit bull.

Some time later, she heard McCollom and Szejnrok come home, followed by screaming and gunshots, she claimed.

She claimed to have kept hiding in her room for another hour before venturing out and discovering the bodies.

However, police quickly found that her story didn't add up. 

Firstly, there was broken glass on one of the victims and on top of the other's phone, which wouldn't happen if the intruder broke in first.

Then, they found the gun just outside Julia's bedroom window, the bloodstained knife on the bathroom counter, and bloody footprints matching her shoes.

None of the many cameras around the outside of the house found any trace of an intruder.

Julia called 911 and allegedly made up a story about hiding in her room while an intruder ransacked the home and killed the couple

Julia eventually broke down under interrogation, and confessed to the murder to detectives, the affidavit explained.

Palm Bay Police Lieutenant Virginia Kilmer said mother and daughter had 'many disagreements in the previous weeks.'

'Egler cited long-standing conflicts with her mother, including disagreements related to her gender transition, as well as disapproval of her mother's relationship with Szejnrok, as motives for the crime,' he said.

Julia transitioned from male to female many years earlier as a young child, appearing as a girl on McCollom's social media pages from at least 2015.

Her posts appeared to be very supportive of her daughter's gender identity, always calling her 'my daughter' and sharing sweet photos of them together.

Szejnrok was arrested by the West Melbourne Police Department on April 14 and charged with domestic battery.

Police at the time said he and McCollom were arguing in public when he repeatedly grabbed her. 

None of the many cameras around the outside of the house found any trace of an intruder

Szejnrok was arrested by the West Melbourne Police Department on April 14 and charged with domestic battery against McCollom, but the charges were dropped

Prosecutors dismissed the charges, and he was allowed to return home to McCollom and Julia.

His older brother Dustin Szejnrok announced his death in a Facebook post but did not explain that he was murdered.

'Hey everyone it’s hard to put into words but it’s easier to share with those who may not have been contacted,' he wrote.

'My youngest brother Matthew Szejnrok has passed away. If you have not been contacted please do not blow up our phones on what happened or how.'

Julia is being held in juvenile detention, but police said she could be charged as an adult. The investigation is ongoing.