MIAMI, Fla. -- The details of why police arrested 18-year-old Tyler Weinman in connection with a string of cat killings and mutilations became public Monday with the unsealing of the arrest affidavit.

Weinman was not in court for his arraignment. His attorney entered a written plea of not guilty.

Details of the warrant written on June 13, the day before the arrest, showed that police based their suspicions on Weinman's odd behavior, a cutting tool they found outside his car and his proximity to where cats were found cut, carved and dismembered.

"It's really important to note there is not one single witness that says Tyler Weinman touched a cat -- not one witness," said his attorney, David Macey, after the court hearing.

Of the 10-page affidavit, the first four pages chronicle the gruesome details of 19 cats' deaths in Cutler Bay and Palmetto Bay, where Weinman splits time between his divorced parents.

The warrant recounts how police doing neighborhood surveillance first stopped Weinman at about 2 a.m. on May 14 as he walked near his Cutler Bay home, then spotted him again the next night, skateboarding after midnight in dark clothing and a backpack. On both occasions, police mentioned the cat killings to him and said Weinman laughed, according to the affidavit.

Later in the day on May 15, police pulled Weinman over in his black Honda on a traffic stop. Detectives said they saw a "cutting instrument" on the ground outside his driver's side door and saw a plastic bag with a gram of pot inside the car. They took Weinman in for questioning.

During the course of an interview, detectives said Weinman attributed scratches he had on his face and back to feeding stray cats. He seemed to know more about catching and dissecting cats than he had learned in biology class at Palmetto High School and excitedly talked about the sound of a cat being skinned, the affidavit said.

He told police he worked as a Swim Gym counselor at Dave & Mary Alper Jewish Community Center. He said he didn't have to go to high school because his grades were "off the charts." He said he "despises" his father, Douglas Weinman, who is the parent who has been in court for his appearances, police said.

Police obtained permission to tap Weinman's cell phone and install a GPS tracking system in his car. With the GPS information, they can place his car near two of the cat mutilation scenes.

Police arrested Weinman on June 14 at a friend's party.

Detectives also searched both parents' homes, taking evidence they have not yet made public. Prosecutors have said some of that evidence has been sent to a lab for testing, but details of the searches are still under seal.

"We have nothing to hide," said prosecutor Elijah Levitt, answering defense attorneys' criticism that they have not been given the reasons and results of the search warrants. "There's actually not a statutory time for when the search warrant needs to be provided. There's no time limit on it."

Weinman is accused of killing 19 cats in the Palmetto and Cutler Bay areas of Southwest Miami-Dade. The affidavit said more than 30 cats were killed and mutilated in the area, but only 19 of the cases were "chargeable."