GAINESVILLE -- A backpack belonging to missing University of Florida student Christian Aguilar was found hidden in the closet of murder suspect Pedro Bravo, and investigators also found blood in Bravo’s SUV, according to an arrest report charging Bravo in Aguilar’s murder.

Police have charged Bravo with first-degree murder in the death of Aguilar, though the body of the Miami-Dade teen still has not been found after nine days of exhaustive searching through the Gainesville area.

Bravo, 18, also from Miami-Dade, was denied bail Saturday morning as he made his first appearance in court.

Bravo, who is on suicide watch at the jail, looked straight-faced into the jail camera during the proceedings, wearing a black spongy suicide-prevention smock stretching from his shoulders to his feet.

While scores of police officers and volunteers — and, for a brief time, Gov. Rick Scott — searched the woods and brush again Saturday for Aguilar, prosecutors said so much time has passed that Aguilar should be presumed dead.

“There is a reasonable assumption that he is deceased," said Bill Cervone, Alachua County’s state attorney.

Aguilar, a UF freshman who graduated from the Doral Academy Preparatory School in west Miami-Dade, disappeared Sept. 20. He was last seen alive that day at a Best Buy store with Bravo, a friend and classmate from Doral Academy.

Bravo, a student at Santa Fe College in Gainesville, told police that he met Aguilar on the UF campus on that afternoon and the pair went to Best Buy and other spots around Gainesville, according to an arrest report. They got into an argument, Bravo told police, because Aguilar had begun dating Bravo’s ex-girlfriend, Erika Friman — also a graduate of Doral Academy, and a Santa Fe student.

Bravo initially denied any physical confrontation with Aguilar, and told detectives that he dropped Aguilar off along the side of the road in northwest Gainesville. He changed his story under questioning: He said he punched Aguilar, forced him from the SUV, then beat him for 10 to 15 minutes “until the victim lost consciousness,” the report says.

Bravo then told detectives he left Aguilar “barely breathing and not moving, lying on his back partially in water” near a Gainesville motorsports shop. Bravo then turned off Aguilar’s cell phone and threw it into the woods, the arrest report says.

Bravo took police to the area where he said he left Aguilar, but they found no sign of Aguilar or the phone, which has a red cover.

“We feel this is a big piece of the puzzle,” Gainesville Police spokesman Ben Tobias said of the phone. “The hope is that it can tell us something about the timeline.”

Detectives searched Bravo’s apartment and found Aguilar’s backpack hidden inside a suitcase in Bravo’s bedroom closet, the report says. Police also found blood stains in “several locations” in Bravo’s Chevy Blazer. The Florida Department of Law Enforcement is rushing a test comparing the blood to DNA samples to determine if it is Aguilar’s.

Police also found a receipt showing Bravo had purchased a shovel and duct tape four days before Aguilar’s disappearance. Neither the shovel nor the tape have been found.

With the help of University of Florida researchers, detectives found traces of lime rock on Bravo’s truck, leading them to suspect that Aguilar’s body “may be located near areas of lime rock,” police said.

More than 300 volunteers — the most so far — joined police on Saturday to scan the brush around Gainesville, but again they found no evidence of Aguilar.

When the search concluded for the day, Aguilar’s father — who implored volunteers from around the state to continue the search for his son did not want to talk about the case.

“My focus right now is finding my son,” he said.

The search will resume Sunday morning.

Before Bravo’s Saturday morning court hearing, a family friend read a statement from Carlos Aguilar:

“The Aguilar family extend their condolences to Pedro Bravo’s family,” the statement read. “They understand that there are two families suffering today. That being said, they do ask that justice be served.”

Ron Kozlowski, one of Bravo’s attorneys, said Bravo’s parents, who live west of Sweetwater, are praying for Aguilar’s family.

“There’s pain on both sides of this case,” Kozlowski told members of the media gathered outside the courthouse.

He said Bravo has been told not to talk to police about the case.

“He drove [police] around town. He showed them what he said he knew,” Kozlowski said. “Since then, he has retained his right to remain silent.”