That action, and the seconds that followed it, have thrust the handicap parking spot dispute into the nationwide debate about "stand your ground" laws.
Now seated on the ground, Drejka reached into his pocket, pulled out a pistol and fired a single shot into McGlockton's chest, an action shown clearly on surveillance video released by the Pinellas County Sheriff's Office.
McGlockton clutched his chest, staggered into the store and collapsed. Later, his girlfriend ran into the store and applied pressure to the bullet wound in an unsuccessful attempt to stop the bleeding.
McGlockton, 28, died a short time later, leaving his family to bury him and the rest of Pinellas County to grapple with the legality of his killer's actions.
On Saturday, Sheriff Bob Gualtieri announced that Drejka would not be arrested or charged with a crime, saying that his actions fell within the legal boundaries of Florida's "stand your ground" law. Then, in an expansive 30-minute news conference, he tried to explain how the law connected to what was going through Drejka's mind when he pulled the trigger.
Drejka "felt after being slammed to the ground, the next thing was he was going to be further attacked by McGlockton," said Gualtieri, who has been sheriff since 2011 and also has a law degree. "He felt the next thing was that he was going to be slammed again. He was going to be struck again and he was in fear."
Reporters asked whether the fact that Drejka initiated the incident made him more culpable - pointing to previous complaints the sheriff's office has received about him.
A few months ago, according to the Tampa Bay Times, Rick Kelly parked his tanker truck in the same handicapped spot and said he was confronted by Drejka.
Drejka walked around his truck, looking for handicapped decals, then demanded to know why Kelly had parked there, the trucker told the Tampa Bay Times. At one point Drejka threatened to shoot Kelly.
"It's a repeat. It happened to me the first time. The second time it's happening, someone's life got taken," Kelly told the Tampa Bay Times. "He provoked that."
Still, Gualtieri told reporters, the legal question is not about whether Drejka was right in being the self-appointed protector of the handicap spot.
"What's relevant is not whether this guy's a good guy, nice guy, or whether he's a jerk, or whether he's a thorn in people's side and what he's done, whether it's three weeks ago, three months ago or three years ago," Gualtieri said. "What's relevant and the only thing we can look at here is was he in fear of further bodily harm."
Floridians have always had the right to defend themselves, but the state's "stand your ground" law says people who believe someone is trying to kill or seriously harm them don't have an obligation to retreat before using deadly force.
The law was spotlighted following the 2012 slaying of 17-year-old Trayvon Martin when jurors discussed the statute in their deliberations before deciding to find George Zimmerman not guilty.
In the past, defence lawyers had to explain why their clients deserved immunity in a killing. Now prosecutors have to prove that people who claim they were standing their ground are wrong.
Last year, lawmakers shifted the burden of proof from defence lawyers to prosecutors. It has made the law no less controversial.
"Does this law create a situation potentially where people shoot first and ask questions later?" Gualtieri asked. "You can have that discussion. You can have that debate. I don't make the law. We enforce the law. And I'm going to enforce it the way it's written, the way the legislature intended for it to be applied, and others can have the debate about whether they like it or not."
It is unclear whether Jacobs and her family will be involved in that debate. She told the Tampa Bay Times she is hiring a lawyer to consider her legal options.
For now, there are bigger things to contend with.
There is a funeral to plan, and also the needs of the living.
After the shooting, as McGlockton bled to death on the floor of the convenience store, his 5-year-old son, Markeis jnr, watched as his mother pressed a shirt to the chest of his mortally wounded father, trying unsuccessfully to keep him alive.
"He's not too good," Jacobs said of the boy, according to the Tampa Bay Times. "It comes and goes, but he knows [his father] is dead."
