The murder of the health care executive Brian Thompson on a Midtown sidewalk was shocking, brazen and seemingly methodical, but it wasn’t all that sophisticated.

It didn’t take long for the authorities to identify Luigi Mangione as the likely murderer and arrest him. They had surveillance videos and various sightings. They are said to have forensic evidence linking him to the crime. A gun he had when he was arrested in Pennsylvania is said to be the same type of gun as the murder weapon. A notebook attributed to Mr. Mangione is said to have mentioned Mr. Thompson’s company, UnitedHealthcare, and that he planned to shoot a C.E.O. “These parasites had it coming,” he wrote, condemning health care companies for callous greed.

In other words, Manhattan prosecutors have what looks to be a pretty straightforward case of second-degree murder, the charge that is almost always filed in New York State in cases of intentional murder.

But the Manhattan district attorney, Alvin Bragg, instead has charged Mr. Mangione with first-degree and second-degree murder in furtherance of terrorism (among other charges), which requires lifetime imprisonment in the event of a conviction. (The maximum sentence for second-degree murder without the terrorism charge would be 25 years to life.)

By complicating a simple case, Mr. Bragg has increased the risk of acquittal on the most serious charge and a hung jury on any charge. Since Mr. Mangione is already being celebrated by some as a folk hero because of his rage against the American health care system, the terrorism charge, which alleges that Mr. Mangione “intended to intimidate or coerce a civilian population, influence the policies of a unit of government” and “affect the conduct of a unit of government,” almost certainly will turn the case into political theater.

By charging Mr. Mangione as a terrorist, prosecutors are taking on a higher burden to support a dubious theory. In trying to prove that Mr. Mangione killed Mr. Thompson to “intimidate or coerce a civilian population,” prosecutors will presumably argue that the civilian population comprises health care executives and employees. But New York appellate courts have taken a very limited and fairly traditional view of what constitutes a civilian community under the terrorism law that was enacted within days of the Sept. 11 attacks.