Tucson police conducted an intensive search — both in the number of people questioned and areas checked — in the hours and days following the disappearance of Isabel Celis, newly released reports show.

Tucson police on Thursday made public more than 500 pages of reports filed by officers who were involved in the search for 6-year-old Isabel, who was reported missing from her midtown home April 21.

The investigation has cost Tucson police more than $1 million and involved hundreds of officers.

Most of the police reports were similar in detail, briefly spelling out each officer’s involvement in the case. Most of the reports were from officers who conducted searches, canvassed neighborhoods or followed up on tips reported by the community.

Some details from the reports include:

• DNA samples were taken from Isabel’s parents and brothers on the morning of her disappearance.

• Officers conducted intensive searches in the area, stopping and questioning all people walking or driving in different areas around Isabel’s home. They also questioned as many residents as they encountered in nearby homes and apartments.

• Officers searched vacant buildings, desert areas, parks and retention basins. Officers also checked backyard pools and in one case, an underground bomb shelter.

• Officers checked out numerous reports in the following days of people seen walking, driving or in businesses with a young girl who looked like Isabel. None of the reports indicated if any of the tips were valid.

In one report, a police officer details how he was approached by a man while standing in line to buy food at a Bruegger’s Bagels. He said the man told him he was a “friend” of Isabel’s father, Sergio, and that he coached baseball with him. The man asked the officer about the investigation and told the officer that “something didn’t seem right about what was going on and alluded that he believed that the father was involved in some way,” the report states.

The officer took the man’s information and forwarded it to his police supervisors.

Also, police retrieved DNA samples from parents Sergio and Becky Celis and Isabel’s two brothers on the morning of her disappearance, one report stated. The officer wrote he took swab samples from the mouths of the family members while they were inside their home.

Another officer’s report said he spoke to a man who had been looking at airplanes in the plane “boneyard” and noticed teenagers digging in the yard. When the officer found the area he said the mounds of dirt appeared to have been used as bike ramps and another area looked as if the teens built forts. No criminal activity was suspected, the officer wrote.

Another officer wrote that he was sent to a motel in the 3300 block of East Benson Highway. Someone called 911 saying he had Isabel and if police did not respond in 10 minutes he would kill her. The officer searched the area and questioned people staying in the motel but nothing suspicious was found.

Another officer wrote that he was assigned to stop people entering and leaving a neighborhood at 12th Street and Van Buren Avenue, east of Isabel’s house, on April 24. His report listed all the people he spoke with, the reason they were driving or walking in the area. Most said they were going to work, school, visiting relatives or running errands.

The officer said that a woman approached him and said the she had been at Sears Park on East 14th Street, south of Park Place mall, and found a small pair of children’s stockings, large shoe prints and tire tracks, a cigarette package and a receipt for a man’s hat. He advised the woman to return to the park and call 911, which she did.

Another officer’s report was 11 pages long, listing the names and phone numbers of every person he and several other officers questioned during a canvass of an apartment complex.

One officer wrote that on April 24 a man told him had had been digging in the trash behind businesses on East Irvington Road and found a plastic garbage bag with maggots and hair inside. Officers went to the business and found the plastic bag, which contained a dead animal.

An officer wrote in a report that on the morning of Isabel’s disappearance, he was canvassing a neighborhood on East 12th Street. He said a family told him about several suspicious vehicles they saw driving in the neighborhood that afternoon — one a Dodge Ram truck another a Honda hatchback. They weren’t able to get license plate numbers, the report stated.

The officer wrote he also searched a nearby house and an underground bomb shelter in the back yard of the house.

In a report an officer wrote about searching the desert area east of St. Joseph’s Hospital on North Wilmot Road. He located a Timex watch with a green wristband that he entered into evidence.

Officers also conducted searches as far as Redington Pass on the far east side as well as tunnels near Craycroft Road and the Williams Center.

The officers also searched the old DeAnza Drive-In theater site at Alvernon Way and 22nd Street as well as vacant buildings nearby.