Prosecutors will seek the death penalty against the 24-year-old man accused of randomly killing four people in Florida and sparking a months-long manhunt, authorities said Tuesday.

Hillsborough State Attorney Andrew Warren revealed his decision in the case against Howell Emanuel Donaldson III during a mid-morning press conference in Tampa.

"The death penalty is for the worst of the worst, crimes that are far more egregious than the typical murder, and that's exactly what we have here," Warren said, adding that Donaldson is accused of killing four people in a "cold, calculating and premeditated manner."

Donaldson, who is charged with four counts of first-degree murder, was caught on Nov. 28 at a McDonald’s near the Seminole Heights neighborhood where the killings took place. Police received a tip that he had brought a loaded gun to his job and asked a co-worker to hold it for him.

The employee told the manager, who alerted a police officer who happened to be at the restaurant.

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Police said the gun, a .40-caliber Glock, was the missing evidence authorities need to connect the killings to the images previously released from surveillance video of the suspect leaving the Seminole Heights neighborhood in Tampa where the victims were apparently picked at random.

The victims, who were killed between Oct. 9 and Nov. 14, were identified as Benjamin Mitchell, 22, Monica Hoffa, 32, Anthony Naiboa, 20, and Ronald Felton, 60.

"A prosecutor's pursuit of justice should be tempered by mercy, but some crimes are so unconscionable, so hard to fathom that we must leave mercy to a higher power and instead focus on achieving justice for the victims and their families," Warren said.

According to prosecutors, some of the families of the victims said they favored the death penalty for Donaldson, while others preferred a life sentence.

In the end, Warren said, all of the families were OK with proceeding with the death penalty.

The Associated Press contributed to this report.