A kind restaurant owner personally delivered $9,000 to a McDonald's worker who helped police catch an alleged serial killer but will likely be denied reward money.

Howell Donaldson III, 24, was arrested on Tuesday on suspicion of murdering four people in Tampa, Florida in October and November.

Police brought him in after McDonald's worker Delonda Walker told an officer in the restaurant that her colleague Donaldson had handed her a bag containing a gun and told her not to look inside.

A kind restaurant owner delivered a $9,000 reward to a McDonald's worker who helped police catch an alleged serial killer

Richard Gonzmart, who owns a restaurant six blocks away, came good on his promise to give $9,000 to anyone who helped police

Delonda Walker (pictured above hugging one of the victim's relatives) told an officer in the restaurant that her colleague Donaldson had handed her a bag containing a gun and told her not to look inside

Richard Gonzmart, who owns a restaurant six blocks away, came good on his promise to give $9,000 to anyone who helped police.

Video shows the moment he went into the McDonald's to personally hand Walker the check.

Gonzmart said: 'She didn't know what to say. She didn't expect anything. I don't think she did it for a reward. That's what makes it even more special.'

The total reward money on offer was $110,000 - but it's unclear whether Walker will receive all of this.

Crimestoppers offered $5,000, $80,000 came from law enforcement partners, $6,000 from community group Rise Tampa, $10,000 from The David Straz Jr. Foundation and $9,000 from Gonzmart.

Crimstoppers' policy says they cannot reward Ms Walker because she did not inform them directly.

The others have yet to comment on whether they will make good their promises.

Police are investigating how much of the money they can give her.

Donaldson (right) is accused of fatally shooting Benjamin Mitchell, Monica Hoffa, Anthony Naiboa and Ronald Felton

Walker, seen above, said: 'I am also appreciative of the outpouring of support from the community'

After receiving her $9,000 check, Ms Walker said in a statement: 'As you can imagine, I am overwhelmed and surprised by yesterday's events and I understand why many are interested in speaking with me.

'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.

'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.'

Ms Walker met on Thursday with members of the family of one of the victims who thanked her for helping to catch the killer.

ABC Action News filmed as relatives of Monica Hoffa, who was shot dead on October 11 in Seminole Heights, hugged the McDonald's manager.

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

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

Officers are processing possible evidence and a red Mustang (pictured) at a McDonald's in Ybor City in Tampa

Alleged killer Donaldson was born in North Carolina but spent most of his life in Tampa before going to play college basketball at St John's University in New York.

On Tuesday afternoon Police Chief Brian Dugan told reporters that a man was brought in for questioning in connection with the murders.

Howell Donaldson's mugshot released by the Hillsborough County Sheriff's Office

The killings started 53 days ago in Tampa's Seminole Height's neighborhood.

Earlier this week police connected the killings based on their methodology.

Each of the four victims was shot dead but not robbed while they walked along at night within a half-mile area of the Seminole Heights neighborhood.

The victims didn't have any common similarities based on race, age or occupation.

The first attack happened on October 9 when Benjamin Mitchell was shot dead after getting off a bus in the neighborhood at night.

Two days after Mitchell, 22, was shot, Monica Hoffa, 32, was gunned down. And on October 19, Anthony Naiboa, 20, was shot after taking the wrong bus home from his new job.

Police patrolling nearby heard the gunshots and rushed to the scene to find Naiboa dead.

Howell Donaldson was arrested after police received a tip from a McDonald's staff member Tuesday afternoon about a man with a gun and brought him in for questioning

The first attack happened on October 9 when Benjamin Mitchell (left) was shot dead after getting off a bus in the neighborhood at night. Two days after Mitchell, 22, was shot, Monica Hoffa, (right) 32, was gunned down

On October 19, Anthony Naiboa, (left) 20, was shot after taking the wrong bus home from his new job. Then on November 14 Ronald Felton (right) was crossing at Nebraska and Wilder when a man dressed in all black came up behind him and shot him

Each of the four victims was killed but not robbed while they walked along at night within a half-mile are of the Seminole Heights neighborhood

In late October police released a blurry video of a suspect, who could be seen wearing a hooded jacket and walking down a street near one of the shootings.

They then released another video on November 16 of a man present near the fatal shooting of Ronald Felton.

Felton, shot on on November 14, was the last of the four victims to be killed.

Police said the victim, a construction worker and father of three adult children, was crossing at Nebraska and Wilder when a man dressed in all black came up behind him and shot him.

A grand jury has until 19 December to charge Donaldson.