TAMPA — One of the most intense dragnets in city history ended Tuesday with a tip to a police officer sitting in a McDonald's doing her paperwork.

The investigation raced from there. A 24-year-old man was taken in for questioning. Crime tape went up. Officers descended on the Ybor City fast food joint, then a family home in Sulphur Springs. Television cameras stood watch. So did residents, wondering what it all meant. Anxious relatives of the victims waited for the news: Was an arrest finally at hand?

That night, Tampa Police Chief Brian Dugan told the city that the six-week hunt for the Seminole Heights serial killer was over.

Howell Emanuel Donaldson III was arrested on four counts of first-degree murder. He is accused of shooting and killing three men and one woman as they made their way along their own neighborhood streets.

TIMELINE: Key events leading to the arrest in the Seminole Heights slayings

The first to die was Benjamin Mitchell, 22, on Oct. 9. About two days later, Monica Hoffa, 32, was shot and killed. On Oct. 19, Anthony Naiboa, 20, was gunned down. The last victim, Ronald Felton, 60, was slain on Nov. 14.

Earlier that day, Dugan cautioned that this new avenue of the investigation was just starting, that police had been let down by tips before.

Later, he admitted sensing that this time would be different.

"It just felt right," Dugan said at the Tuesday night news conference. "I kind of had a feeling that we were going to get a break."

• • •

The break police were waiting for came around 2:30 p.m. Tuesday. That's when Donaldson showed up at the McDonald's at 2101 E 13th Ave, where drivers exit Interstate 4 to reach historic E Seventh Avenue in Ybor City.

McDonald's employee Gail Rogers said Donaldson had worked there for just two months. He was wearing his McDonald's uniform and showed up in a red Mustang, possibly his father's car.

GALLERY: Tampa police seize gun, question McDonald's employee

Rogers said Donaldson asked the manager to hold onto his semiautomatic pistol for him. She said it was loaded. Then Donaldson walked to Amscot to get a payday loan. Police said he was a crew leader at the restaurant, but Rogers did not know if he was working that day.

The manager didn't know what to do with the gun. Rogers said she huddled with the manager and told him to alert an officer inside the restaurant.

The manager told the officer about the gun. Backup was called.

As Donaldson walked back into the McDonald's parking lot, officers were waiting. Police took him away, saying only that he was being questioned.

The restaurant was quickly surrounded by officers, who blocked it off with crime scene tape as they examined the red sports car. As word spread, a relative of one of the victims went to the McDonald's.

"I just want to see what's going on," said Casimar Naiboa, whose son Anthony was killed. "I want to know what is happening. I want to see this guy behind bars."

Why would Donaldson leave the weapon at the restaurant, with his manager? That was one of the questions police did not answer after the arrest.

The investigation quickly spread to a Sulphur Springs street where records show his family owns a boarded-up house. Two police sport-utility vehicles closed part of the street, More officers arrived as the sun set.

RELATED: Sister of Seminole Heights murder victim now dealing with her husband's death

Dugan said they had received more than 5,000 tips during the six-week investigation. Over that time residents grew fearful and police grew frustrated. Officers faced two challenges: They had to solve the murders and prevent more from taking place.

The police presence in Seminole Heights was heavy. Undercover officers flooded the area and police warned residents not to walk alone. Officers made their presence well-known during Halloween trick-or-treating and monitored school bus stops. Officers even patrolled on horseback.

It was the largest law enforcement operation undertaken in Hillsborough County since the 2010 search for Donate Morris after he killed Tampa police Officers David Curtis and Jeffrey Kocab during a traffic stop. The manhunt took four days, involved hundreds of officers and reached North Carolina.

Just like the Seminole Heights' murders, the Morris saga was also one of the deadliest episodes in Tampa history. He was linked to five murders and now sits on Death Row for three of them. And like the Morris case, the search for the Seminole Heights suspect ended just miles from the scene of the murders.

Donaldson had just been taken in for questioning Tuesday afternoon when the chief briefed the media outside the McDonald's. He expressed caution about this latest tip, and frustration at all the others that had not panned out.

RELATED: 'I just hope they find that killer': Family, friends mourn Seminole Heights murder victim

"We've had that before and, unfortunately, it's led to nothing," Dugan said. "I'm guarded because I've been on this road before. It's day 51 days that we've been doing this. It's been two weeks since Ronald Felton was murdered. It's been a long time for the families and the cops, and so I'm guarded on the whole thing but I'm very optimistic.

"There's a lot to go through, a lot to sift through, and it's going to take many things to fall in line."

That afternoon, the victims' families were also guarded.

"I am nervous ... I want this to be the end of this," said Kenny Hoffa, 52, whose daughter Moncia was the second victim. "It is like riding a roller coaster right before you go over the edge and you feel your stomach raise up in your face."

Bettie McDaniels, the aunt of Benjamin Mitchell, the first victim, said that afternoon that she was "waiting for police to say they really got him."

"I hope it is him, but I am waiting to see," she said. "I just hope it is the Lord's will that they catch him."

• • •

It was 11 p.m. when Dugan addressed the media at police headquarters.

"I am pleased to announce that tonight we will be making an arrest in the Seminole Heights murder," he said.

The chief cautioned the public that his detectives were still preparing the official paperwork for the arrest.

Dugan also would not say if Donaldson had confessed or made any statements to police.

Nor would police say if the gun they recovered from the McDonald's was linked to any of the murders, or if it was the same caliber as the weapon used in those slayings. Jail records listed a .40-caliber Smith and Wesson handgun under each murder charge.

There were many details about the investigation that the chief said they could not yet discuss.

"Unfortunately I will not have the answers that you want," Dugan said. "This is an ongoing situation."

Among the questions police still need to answer, he said: "We're not sure why he was in this neighborhood. We're not sure what his ties are or what motivated him."

RELATED: Mounted police patrol Seminole Heights after killings

Mayor Bob Buckhorn expressed relief that the manhunt was over.

"Fifty one days ago I said this was a struggle between good and evil," he said. "Well, tonight goodness has won."

Dugan said officials decided to make the quick announcement to send a message to the residents who spent weeks living in fear of a terrible mystery:

"Our real goal was to let the people of Seminole Heights get a good night's sleep."

• • •

Before the official announcement, police told the victims' families.

Casimar Naiboa, whose son Anthony was the third victim, went to the McDonald's that afternoon to see what was going on.

Hours later, Detective Austin Hill told the father the news.

"I was speechless," Casimar Naiboa said. "I was happy they finally got this guy, but at the same time, I couldn't believe it.

"Finally, this nightmare is over."

While the news conference unfolded in downtown Tampa, he sat in his son's room and talked about what the arrest meant to him.

"We are relieved, I am thankful for the police, for everybody, who supported the families in these moments of grieving and pain," the father said. "It is just a relief that finally this guy is off the street, no more scaring people, and hurting people. He won't be killing anyone else and hurting families. Now we have to see the face of our son's killer."

"Seeing this guy standing there, it hurts, it hurt me. This guy killed my son, this coward."

Dugan called and texted Kenny Hoffa the news. Monica Hoffa's father said he was overjoyed. He intended to drive straight to Tampa from his home in Charleston, S.C.

"I know this is step one of this process," the father said. "Like the mayor said, I hope this guy rots in hell. What was this kid thinking. He was just 24 years old. I'll be heading that way in the morning."

RELATED: On the night shift in Seminole Heights, Tampa police keep watch for a killer

Now the families will have to steel themselves for the next chapters. The investigation will continue, more details will be revealed, family and friends of the accused will speak out. And then, eventually, there will be a trial — and the accused will be entitled to a defense.

"There is no closure, not really," Casimar Naiboa said. "It brings us relief that this guy is no longer laughing, walking free and walking around with impunity.

"My son will never have Christmas and things like that. I am sitting in my son's room right now and my son is not there. I have my son's TV, but he is not lying down. He is not going to work tomorrow. I cannot say anything to my son. There is never going to be closure."

Like the police chief, the father said that he, too, sensed a resolution was at hand. That's what he told his son Anthony Naiboa earlier that day:

"I went to the cemetery this morning and I talked to my son right in front of his grave and told him that we would find this guy."

• • •

Twelve hours after Donaldson showed up at McDonald's, a Tampa police cruiser pulled into the sally port at the Orient Road Jail. It was 2:25 a.m. Wednesday.

Donaldson emerged from the back seat wearing a white jumpsuit, his hands cuffed behind his back.

Two Tampa officers and two Hillsborough sheriff's deputies escorted him into the booking area.

The 24-year-old man said nothing.

Times senior news researcher Caryn Baird and staff writers Steve Contorno, Melissa Gomez, Zachary T. Sampson, Dan Sullivan and Chris Urso contributed to this report.