Florida teen, 19, guns down his father and then executes his mother in front of cops responding to her desperate 911 call

A ‘monster’ teenager shot his father and then executed his mother at point-blank range in front of police before dying in a police shootout.

Police say they received a call just after 11 p.m. Saturday from a woman — later identified as Rebecca Ann Themelis, 48 ​​— reporting that her husband, Christos Byron Themelis, 51, had been shot.

More gunshots were heard while she was on the phone with dispatch, the Hillsborough County Sheriff’s Office said.

By the time officers arrived at the home on Cactus Wren Place in Tampa, Florida, they found the suspect – Christos Alexander Themelis, 19 – and his mother, Rebecca, outside.

As officers watched in horror, the suspect shot his mother in the back of the head and began shooting at the officers, wounding one officer, the sheriff’s office said.

Dramatic body camera footage captured the standoff between Christos Alexander and the officers, beginning when they arrived on the scene and found him outside with his mother.

“Show me your hands, show me your damn hands,” Deputy Shane McGough, 26, was heard shouting.

He then begged Rebecca to “get out of the house now” and walk towards him, holding his gun drawn before radioing in: “He’s got her at gunpoint.”

“Listen, we don’t want to hurt you, just let your mom walk to us, let her walk to us, okay?” McGough tells the suspect and repeats his instructions to “keep your hands up” and “don’t reach behind your back.”

As the son apparently retreats to get his gun, McGough again begs the mother to “walk to me, walk into my flashlight.”

When Christos Alexander returns with the gun, he pleads, “Madam, get away from him now and come here.”

Seconds after the suspect pleads to “stop reaching into your waistband,” gunshots are heard on the bodycam footage as both sides exchange fire.

McGough was hit in the leg, shouting to his fellow officers “I’m hit” and asking for a tourniquet.

Five officers returned fire, causing the suspect to retreat to his home, the sheriff’s office said in a press release.

At that point, authorities deployed a SWAT team and officers used a robot to enter the house through the front door.

“Unfortunately, the first person we encounter on scene is the father,” Sheriff Chad Chronister said at a news conference.

“The father succumbed to his injuries.”

Police then found the suspect dead from injuries sustained during the shooting in another room of the house.

But the situation could have been much worse, Sheriff Chad Chronister suggested.

“The monster we encountered tonight is not only responsible for injuring our deputy, but also for killing his own mother and father,” he said in a statement.

“Our officers responded to a chaotic scene and immediately placed themselves in harm’s way to protect our community.

“Without the quick and skilled response of our deputies, an entire neighborhood would have been in danger.”

None of the officers involved in the shooting had ever used force before, the sheriff’s office added.

Deputy McGough is now in stable condition and underwent surgery Sunday to remove the bullet and insert a rod into his leg to regrow the tibia, which was broken during the shooting.

Authorities said the incident was not the first time police were called to the Tampa home.

Officers have responded to incidents at the home 10 previous times, with the majority related to mental health concerns and violence against the suspect’s parents, Chronister said at the news conference.

He noted there was also an active risk protection order against the 19-year-old, which led officers to confiscate his weapons.

Investigators are now trying to determine how Christos Alexander could have obtained the gun if he was considered “mentally unfit.”

“We don’t know exactly and may never know why he became so violent,” Chronister said.

“But we do know that causing injury or harm to another human being – no matter what the reason is – it is never okay. Period of time.’