Phoenix police have in custody the two men they believe are responsible for a slew of shootings that had paralyzed the area with fear in recent months, officials said Friday.

Police said during a press conference Friday that they believe Dale Hausner and Samuel Dieteman are the men who police have dubbed the "Serial Shooter," who they believe to be responsible for three dozen shootings of people, dogs and horses. Phoenix officials say they are waiting to release photos of the suspects pending their identification in a police lineup.

"They are the serial shooters that this task force has been hunting," said Phoenix Police Chief Jack Harris, adding that the men will face numerous counts of murder and aggravated assault, though authorities didn't have specifics on how many.

"This morning I am a grateful mayor," said Phoenix Mayor Phil Gordon. "These are the two monsters we've been hunting, and I promise you and our colleagues promise you, we are not finished."

Visit FOXNews.com's Crime Center for complete coverage.

Assistant Police Chief Kevin Robinson said Hausner, 33, and Dieteman, 31, are friends who lived in Mesa. Investigators found no obvious connections between the two men and the victims, Robinson said.

"The best we could tell, they were just random victims. These individuals just picked victims out and that was it," Robinson said.

But police are also trying to track down another serial criminal dubbed the "Baseline Killer," who is believed to be responsible for killing seven women, one man and sexually assaulting 11 women and girls during the past year. Police think this killer's most recent victim was a 37-year-old woman at a Phoenix car wash June 29.

Police were hesitant to give too many details about how they determined these two men may be the Serial Shooters, but they said they wanted to assure the public that the men are "the right guys." They said there appears to be no relationship between the men and the Baseline Killer, however. Police who had been working on the Serial Shooter case will now focus all of their efforts on finding the Baseline Killer, officials said.

The two men were apprehended at Windscape Apartments in Mesa early Friday morning after a search warrant was obtained. Investigators were seen Friday walking out of the complex with several firearms. A vehicle was also seized.

"It had nothing to do with a traffic stop," Sgt. Andy Hill told reporters Friday morning. "It had nothing to do with information from a particular meeting."

The local FOX affiliate reported that one of the two men in custody is believed to be one of the shooters, and the other man is believed to be the driver of the vehicle the shooter rides in while he targets his victims.

Phoenix police said it was a combination of tips from the public and dogged law enforcement that led to the apprehension of the suspects.

Robinson said investigators identified them as suspects Monday evening, but added that they had some information about them before that.

"It wasn't just one source," Robinson said. "We were able to get on these individuals from a lot of different sources."

Once police thought they had the shooters, Robinson said they spent the next four days gathering evidence, interviewing witnesses and watching the suspects so they had enough information to confidently arrest and hold them.

"We are confident these are the individuals involved," Robinson said.

Police think six people were killed by the Serial Shooter and 17 — mostly pedestrians and bicyclists — have been wounded since May 2005. Police announced Thursday that the weekend death of a 22-year-old woman who was gunned down while walking was the latest victim of this killer.

Loraine Salyers, a resident of the apartment complex, said she lives near where police came in early Friday.

"I came out and there were like a hundred cops," Salyers said. "I was so scared. My heart's pounding."

The recent rash of killings has forced many residents to stay inside and not walk around alone.

Phoenix police have had about 200 officers working to try to solve the cases. A $100,000 reward is being offered for any information leading to the capture of either killer.

Before Friday's arrests, police had said they had no idea who the Serial Shooter was, what he looked like and whether he was working alone.

"I hope they got him," said Caroll Roberts, whose 19-year-old son was shot in the torso last month and survived after four hours of surgery. "I want to shoot him in the stomach to see how he'd like it, like he did my son."

Robin Blasnek, 22, was gunned down at about 11:15 p.m. Sunday. Neighbors heard a shot and ran to help the young woman, but she soon lost consciousness and died at a hospital. Click here to read more on that story.

The shooting was linked to earlier cases because of similarities and forensic evidence, authorities said.

Blasnek's father told the East Valley Tribune that his daughter grew up as a special needs child, and lived part time with her parents in Mesa and at a group home in Tempe.

"She was just a great kid. Very, very naive, and pure as far as not understanding the dangers of the world," Steve Blasnek said. "I guess my only regret is that I didn't give her a big hug."

The Associated Press contributed to this report.