Eight male neighbors and friends who were in the home of Elizabeth Smart within hours of her kidnapping have been asked by the Salt Lake City Police Department to provide blood samples and fingerprints by Monday, Fox News has learned.

Five of the eight neighbors sought by police submitted to the tests, police said Monday. Three of the men were out of town but authorities said they planned to comply when they return.

Ed Smart, 14-year-old Elizabeth Smart's father, ran up and down the street alerting his neighbors when he noticed his daughter was missing — many of them came over and had gathered inside before the police arrived.

Investigative experts told Fox News one reason authorities are requesting the blood could be because law enforcement has male DNA they've collected which does not match the family and they need to compare it to every male they know of who was in the home.

The man who police say tops their list of potential suspects in the 14-year-old's disappearance, Richard Albert Ricci, has already given blood and hair samples — and has given two polygraphs.

Ricci said in a statement late Friday that he doesn't have any knowledge of where Smart could be found.

"I would not — nor could not — hurt a child in any way," Ricci said in the statement. "I have no knowledge of Elizabeth Smart's abduction, disappearance or whereabouts."

Ricci also speculated he has been targeted by police because of his 29-year prison history. "I think the reason I'm involved is because of my past," he said.

Smart was taken from her home in the early hours June 5. Ricci, 48, worked at the Smart home as a handyman more than a year ago. He hasn't been charged in the case, but police haven't yet ruled him out as a possible suspect.

Ricci's wife has said he was asleep in bed when the girl was kidnapped.

Earlier Friday, a new arrest warrant and possibly a second were issued for people who might be connected to the disappearance. At least one of the men lives in the same trailer park as Ricci.

Sources told Fox News that the one confirmed arrest report is a very similar situation to the Ricci arrest. Both were taken into custody on other, lesser charges not connected to the abduction. The second man could at least prove to be a witness if it's found that he is not involved in this case. Investigators say they're hopeful his arrest will bring them closer to a conclusion.

The investigation centered Friday on a tan golf cap that law enforcement officials have removed from Ricci's father-in-law's house.

Authorities were also looking into how the mileage on Ricci's jeep increased about 1,000 miles between May 30 and June 8.

Additionally, Fox News has learned that authorities are investigating two suspicious cars that were seen in the parking lot of a children's hospital within a mile of the Smart family home at the time of the kidnapping. One of the cars was flashing its lights, and the FBI has captured the car's license plate from a video surveillance tape used by the hospital.

The FBI is considering releasing the license plate number to the public for help in determining why the cars were there.

The golf cap is in the custody of police and FBI investigators, who are asking employees of the greenhouse where Ricci worked if they saw him wearing it. They're also talking to convenience stores near his home to check their video surveillance cameras in case Ricci stepped in wearing the cap.

They've ruled out as a possible clue a machete agents took from Ricci's father-in-law's shed after the state crime lab determined there was nothing to tie it to the investigation.

Ricci's father-in-law, 68-year-old Dave Morse Sr., said Thursday that the FBI took the large knife from his house and a hat similar to the one the girl's sister said the abductor was wearing — one of two Scottish-style golf hats he has. He said both hats had remained in his home and were never loaned to his son-in-law.

Morse said he uses the knife that was taken to knock limbs off trees. He said it was always locked in the shed, and Ricci didn't have a key.

"I think they're grasping at straws," Morse said. "There's always a chance, but I don't think he did it."

Ricci's lawyer, David K. Smith, who told The Associated Press that comments by police suggested they are trying to focus on Ricci as their primary suspect, was skeptical about the hat report.

"A lot of people have golf caps here in Salt Lake, as elsewhere," Smith said Friday on NBC's Today show.

Ricci's lawyer addressed a neighbor's statement that Ricci had been seen digging a hole outside his mobile home.

"There was an area that was apparently under the home where cats were getting in and out of, and he was trying to cover that up," Smith said. "Apparently the police also have investigated that, they've gone out, they've dug up the area, they took off the porch. To my knowledge, they haven't found anything."

On Thursday, a federal grand jury met for a second day to question people who may have knowledge of the abduction.

One of the witnesses, Neth K. Moul of West Valley City, told The Associated Press that he testified about seeing Ricci on June 8, three days after the abduction.

Moul, a mechanic, said Ricci brought his 1990 Jeep Cherokee into his shop on May 30 for work.

On June 8, Moul said, Ricci returned the Jeep to the shop for more work. Moul noticed that since May 30, around 1,000 more miles were on the car's odometer.

Moul said Ricci folded up the covers that had been on the vehicle's seats and put them in a plastic bag. "He tied it," Moul said. "There was something already in there because the bag was full.

"He told me he had a friend waiting across the street," Moul said. "There is a gas station. He walked toward the gas station."

That was the last Moul saw of Ricci, who never came back to pick up the Jeep. The FBI contacted him, and soon two or three FBI agents and detectives from Salt Lake City arrived to take the car. Moul, whose story was scheduled to be part of ABC's Primetime Thursday program, said he wasn't sure when authorities took the car, but thought it was about a week ago.

Police on Tuesday handed out fliers with pictures of three cars Ricci has driven, including the white Cherokee. Ed Smart, Elizabeth's father, gave Ricci the car in exchange for some handyman work last year.

Also subpoenaed to appear before the grand jury was Andy Thurber, Ricci's neighbor. He had been set to appear before the jury Wednesday, but told reporters he hadn't taken the stand.

Thurber said he spoke to Ricci on the morning the girl disappeared. "He said he would get questioned," Thurber said.

But Ricci had apparently not been subpoenaed to appear before the grand jury or otherwise called away from the Utah State Prison, where he is being held on an unrelated parole violation.

"He is in there and waiting for his attorney," prison spokesman Jack Ford said Thursday.

Ed Smart said he never would have employed Ricci had he known of his criminal history.

"He seemed to be fairly competent," Smart said. "He seemed nice enough."

The Associated Press contributed to this report.