• Three more cats found skinned on owners' lawns this week • Authorities fear killer could move on to human targets

This article is more than 11 years old

This article is more than 11 years old

A reward has been offered for the arrest of serial cat murderer thought to have killed at least 25 pets near Miami.

Three cats were found skinned and gutted on their owners' lawns this week, in the latest in a string of attacks over the last month in Miami-Dade county.

Authorities warned residents to keep their cats indoors at night, but police said they were no closer to catching the culprit. Experts fear that the perpetrator may move on to murdering humans.

"This man is getting bolder and bolder. The cat that was found this morning was skinned from the waist down, and that takes longer and longer. It is very frustrating and it is heart-wrenching," Dee Chess, founder of Friends Forever animal rescue told the Miami Herald.

The latest victim belonged to a Palmetto Bay resident, John Wellons. According to police, his pet's stomach had been sliced from front to rear. Its skinned corpse was found in Wellons' garden.

He last saw his cat alive on Monday at 7pm, police said. On Tuesday morning it was lying dead in his yard. According to residents, the cats' bodies have been left like trophies on their owners' gardens since early May.

"Anyone capable of mutilating a cat, let alone 18 cats, is certainly capable of hurting people," Jennifer Hobgood, the Florida director of the Humane Society, told CBS4 News last week as she announced a $2,500 (£1,560) reward for information leading to an arrest and conviction.

The reward was increased to $3,500 (£2,185) by Crime Stoppers. Tax-deductible donations are being invited to increase the reward amount.

The killings have caused panic among local pet owners, and the Cat Network rescue organisation has offered cat traps to help residents look after strays. People were urged to keep outside lights on or connected to a motion detector.

Cindy Hewitt, of the Humane Society, told the Herald bereaved pet owners were hampering the investigation by removing the bodies from their lawns before calling the police.

"I can appreciate the emotion behind that, but police need to examine the crime scene," she said. "It's just as important with an animal murder as with a human. If you find an animal that may be a victim, don't touch it."

Detective Bobby Williams, of Miami-Dade police, appealed for help, saying: "However small the information might be, it might be something we can use in the investigation."