Revealed: Tampa teen Christos Alexander Themelis used the gun his mother bought to protect herself from 'monster' son to kill his parents in bloody murder spree

'Monster' teen gunman Christos Alexander Themelis murdered his parents in cold blood with a weapon obtained by his mother after cops seized his guns in a court order due to his disturbing behavior, DailyMail.com has been told exclusively.

Themelis, 19, was handed a finalized Risk Protection Order in April but is believed to have used mom Rebecca's newly acquired pistol to callously shoot her in the back of the head in front of police in a horrific stand-off outside the family home in a quiet Tampa, Florida, neighborhood.

The only child had already executed 51-year-old father Christos Sr inside the four-bedroom house when deputies from Hillsborough County Sheriff's Office arrived and found him out front with his terrified mother, 48.

Horrified officers watched as he blasted Rebecca after they yelled for her to reach safety, sparking a dramatic shootout in which a cop was wounded and the teen gunman died.

Neighbor Troy Cann, whose home was used as cover by officers, told DailyMail.com exclusively: 'Cops took all his guns away because of that court order, but the mom then bought one herself. That is known in the neighborhood.'

Christos Alexander Themelis (center) is believed to have used his mother Rebecca (left) own gun to murder his father (right) and execute his mom

Themelis had his own weapons confiscated by police in April after a Risk Protection Order was finalized because he was deemed a danger to himself or the public

Pointing across to the street to the scene of the carnage, he continued: 'He killed her with her own gun right there in the front yard. It was some kind of pistol.'

A Risk Protection Order in Florida can temporarily restrict a person's access to firearms and ammunition if they are considered a danger to themselves or the public.

HCSO could not confirm to DailyMail.com how Christos Alexander obtained a weapon in light of the order – or if the gun used was bought by his mother 'because it is still an active investigation.'

Records obtained by DailyMail.com show the sheriff's office began the application in February, 2023, and proceedings continued until a final order issued on April 3 this year. At one point Rebecca was served with a subpoena over the case.

Meanwhile, Cann, 53, and other neighbors have painted a picture of Themelis as a mentally disturbed loner who paced local streets at all hours – often latching on to female dog walkers in a bid to chat with them.

The construction supervisor said the killer also frequently shouted and harassed homeowners and would stand in the street and point an unloaded air pistol at him.

Cops had previously been called 10 times to the Themelis home, often by anxious locals, because of loud and escalating arguments between the killer and his parents that spilled outside, DailyMail.com has learned.

Horrifying body camera footage captured the moment Themelis shot his mother in the back of the head then began firing at the officers

And teacher Gladys Moreno, who lives opposite the house of horror, chillingly revealed: 'Everyone round here was expecting something like this to happen one day.'

Asked if she meant as serious as this tragedy, the dual English/Spanish language specialist replied: 'Yes, with guns. Everybody thought it would be this bad. They were always having loud arguments outside and people would call the police.'

Cann said of Themelis: 'He'd walk around with a little kind of air pistol and stand in the middle of the street right there pointing it at me while I was on my driveway.'

'It wasn't loaded, but he'd cock it so it made a popping sound when he pulled the trigger. He'd aim and it would just go pow, pow, pow, pow. No pellets, no nothing, just pop.

'Other times you'd see him pacing around the streets during that day and in the middle of the night, often talking to himself.

'He'd threaten people. He'd yell at people, he was loud. But he also seemed desperate to talk to people in the street. He'd latch on to folks walking their dogs, and he particularly focused on women dog walkers. I start early and sometimes he would be out there walking at four in the morning.

Desperate Rebecca called police just after 11 p.m. Saturday, saying her husband had been shot. More shots were heard on the call when she was talking to the dispatcher, the sheriff's office said.

Deputy Shane McGough (pictured), 26, was shot in the leg during a standoff with the teen gunman after pleading with Rebecca to walk towards him

Deputies arrived within minutes to the scene in northwest Tampa. Dramatic bodycam footage from Deputy Shane McGough, 26, reveals the officer on Cann's driveway pleading with the mom to walk towards him.

McGough, shielded by Cann's Chevrolet Silverado pickup truck, radios in 'he's got her at gunpoint.' The cop then shouts to Themelis: 'Listen, we don't want to hurt you, just let your mom walk to us, let her walk to us OK?'

His voice rising, the cop shouts: 'Keep your hands up… do not reach behind your back.'

It appears the teen then retreats and grabs a gun. McGough again pleads for the mom to 'walk to me, walk into my flashlight… ma'am get away from him now and come here.'

However, seconds after the officer shouts to Themelis 'stop reaching into your waistband,' gunshots can be heard followed by an exchange of fire involving fire deputies. McGough, struck in the leg, yells 'I've been hit' and asks fellow officers for a torniquet.

A SWAT team and a robot entered the house, finding the father dead on the floor and the killer son also dead from police bullets in a different room, HCSO said.

Sheriff Chad Chronister branded the killer 'a monster' who 'is responsible for not only injuring our deputy by also killing his own mother and father.'

Cann gave a dramatic account of the shootout to DailyMail.com, saying: 'I was woken around 11 by this pop, pop, pop. So I run out of my front door and the cop is shot right there… blood stains on the driveway.

When deputies from Hillsborough County Sheriff's Office arrived,  51-year-old father Christos Sr  was already dead inside the house and the teen was outside with his 48-year-old mother

Neighbors told DailyMail.com the family had been arguing the night of the murder and the cops had been called to the Themelis household for domestic numerous times in the past

Others noted Themelis' (right) odd behavior and said he would accost people on the street, harass female dog walkers and had even pointed at gun a neighbors

'And his partner is yelling at me, get back inside, lock your door and take cover. I was that close to the wounded cop to drag him in but his partner yelled again for me to get back inside.'

'That's when even more bullets started flying. There were rifle shells right next to my truck. Then it died down. I went into my garage through the inside door and I could hear SWAT guys on my driveway.'

He said of Themelis: 'It was obvious the kid was mentally disturbed. After I moved here last year my sister pulled up in the driveway with her window down.

'He rushed over and gets in her window. I'm there also, thinking, dude, no way, that's not cool. You gotta go, and I told him. Right then I knew something wasn't right.'

'This is a nice quiet blue collar neighborhood with a lot of retired folk. And the whole neighborhood knew about him because he'd just cause problems.'

Moreno, 61, who has lived opposite the family for more than 20 years, said: 'That boy was mentally ill and he did not get the appropriate treatment.'

'Everybody round here used to hear the arguments from that house. The police would be called. They would come several times but then go.'

On Saturday night, she again heard arguing over the street and ventured outside to see exactly what was happening. 'I see them, the boy is coming in and out, in an out. He's with his mom and dad and he keeps arguing. And it's loud,' she told DailyMail.com.

'I went back inside, not sure what to do.' Moreno is unclear about what she heard next, but within minutes police had arrived in force.

She went upstairs for safety with her husband Victor, fearing to look out. 'I was afraid, it was too close to me. It was dangerous,' she said. 'Everything seemed to happen so fast.'

Days after the horror, evidence of the gun battle remains clear. Two bullet holes are visible near the front door of the Themelis home and there's what appears to be a large blood stain on the path leading to it. A window by the front door is covered by cardboard. There's also a bloodstain on neighbor Cann's driveway.

Family members told DailyMail.com they are shocked about the news and the killer's parents, originally from Massachusetts, had moved to Florida for a better life

One neighbor said Themelis was mentally ill and they suspected something horrible would happen at the house saying, 'everybody thought it would be this bad'

Both the killer's parents are originally from Massachusetts and moved to Florida in 2003, where Christos Sr founded a moving company called Christos & Christos. He is from a large Greek Orthodox family.

His uncle Stephen Themelis, of Lowell, Massachusetts, told DailyMail.com: 'We are all so shocked. We just don't know how to decipher and understand it.'

'Because they were down in Florida, I didn't really have much to do with Christos Alexander. Clearly he was a troubled child, but only his mother and father would really have any answers.'

'Christos Sr was my nephew and I was also his godfather. He and Becky had the guts to make a new life for themselves in Florida and start a business, for a better future.'

'But this is like a disconnect. Everything's good and then all of a sudden it isn't. And you think, it can't be true.'

Rebecca's 75-year-old mother Maria Jennings tearfully told DailyMail.com at her home in Clearwater, Florida: 'I've lost my daughter. I just can't add anything to that.'

HCSO office confirmed to DailyMail.com that Themelis died from his injuries in the shootout and did not take his own life, as per some reports.

Wounded deputy McGough was released from the hospital after a bullet was removed from his right leg and a rod installed for support. His recovery is expected to take three months.