By Eric Levenson, CNN

(CNN) -- A McDonald's manager who gave police a loaded gun that led to the arrest of a suspect in a series of killings in Tampa will receive a $110,000 reward.

Delonda Walker's tip led to Tuesday's arrest of a man who police said killed four seemingly unconnected people in October and November in the city's Seminole Heights neighborhood. The killings terrified residents, and police swarmed the area for weeks amid an intense search for the killer.

Police and victims' families have praised Walker, the manager of a McDonald's in Tampa's Ybor City neighborhood, but there were questions over what the size of her reward would be.

But those questions were put to rest Friday.

Walker has already received about half of the $110,000 reward, according to Christina Barker, an assistant to Tampa Mayor Bob Buckhorn.

Police said Howell Donaldson III, an employee at the same McDonald's, had put a firearm in a food bag and gave it to Walker for safekeeping on Tuesday. At about 2:40 p.m., Walker gave the firearm to a police officer in the fast-food restaurant, who then called for backup and detained Donaldson.

She also told police that Donaldson had expressed his intention to leave the state, according to a criminal affidavit.

That firearm was used in all four of the fatal shootings in Seminole Heights, according to the criminal affidavit. Donaldson admitted that the gun belonged to him, leading to his arrest, the affidavit said.

Donaldson is accused of killing Anthony Naiboa, Monica Hoffa, Benjamin Mitchell and Ronald Felton. He faces four counts of first-degree murder.

Tampa Police Chief Brian Dugan said the gun was a big break in the case that led to the arrest.

"We've had other guns, but we knew this was the one," he said Wednesday.

Dugan added that the employee who came forward did the right thing.

"The person who called us -- I cannot thank them enough for standing up and doing the right thing and saying, 'This doesn't seem right, why does this person have a gun in a bag?' "

'She's a hero to all of us'

In a statement to CNN affiliate WFTS, Walker said she was "overwhelmed and surprised" by the events leading to Donaldson's arrest.

"At this time, I am speaking exclusively with police and am appreciative that they were nearby and quickly acted upon the information I discovered and shared with the police officer," she said. "I am also appreciative of the outpouring of support from the community. My thoughts are focused on the victims and their families and out of respect for them and the active investigation, please direct inquiries to the Tampa Police Department."

Monica Hoffa's family told WFTS that Walker was a hero for helping solve the case.

"She took all of that worry that was out there away, and she made us all whole again," said Kenny Hoffa, Monica's father.

"She's a hero to all of us and our family. She's part of our family now."

A number of groups had offered rewards for anyone who provided tips that led to the suspect's arrest.

The $110,000 reward comes from several of these organizations, including $50,000 from the FBI, $20,000 from the Bureau of Alcohol, Tobacco, Firearms and Explosives and $10,000 from the Florida Department of Law Enforcement.

Crime Stoppers of Tampa Bay initially said Walker was not eligible to receive its $5,000 reward money because she did not actually call the tip line, although the group later put out a statement saying the money would be paid out, according to WFTS.

However, local businessman Richard Gonzmart personally delivered a $9,000 check to her Thursday, making good on his promise to contribute to the reward.