Attaching razor blades to children's playground equipment, similar to what was discovered Monday in an East Moline park, has occurred in other areas of the country.

In 2009, two New York state communities had similar cases within months of each other. Those two cases, along with others across the country, still have officials wondering why anybody would commit such a crime and changing how they patrol parks.

As of late Wednesday afternoon, East Moline police still don't know who glued razor blades to monkey bars, a tube slide and a ring bridge in a playground at Millennium Park on Monday.

Capt. John Reynolds said evidence, including the 12 blades that were found, have been sent to a crime lab to be processed.

"We are continuing to patrol the parks," he said.

In March 2009, the Dutchess County, N.Y., Sheriff's Office investigated a case in Pleasant Valley where a 6-year-old boy was cut by a razor blade while going down a slide.

Capt. John Waterson said the blade had been inserted into the slide through a hole created from underneath "so that just the edge of the blade stuck up into the slide and would cut anyone sliding down past it."

The playground was part of an apartment complex. Police identified an 11-year-old suspect a day later after talking to other children in the complex, Waterson said.

The suspect was charged as a juvenile. Waterson doesn't know where the child got the idea to use razor blades in a slide.

"I don't believe it was a copycat," he said. "It was an isolated incident that caused quite a bit of shock in the community. There's sick people out there."

That July, police found multiple razor blades in a school playground in Morristown, N.Y. No one was injured.

Morristown Mayor Cheryl Shatraw said her town responded by inspecting all other parks in the area, and the school had the playground closed for several weeks, even after the school year began, so police could investigate.

"How in the world could somebody do that, especially when kids play in the playground?" Shatraw said. "Obviously, somebody could have been seriously hurt."

She said a 14-year-old suspect was caught quickly.

"Parents were outraged," Shatraw said. "There was no reason for it. If it was a grudge, you certainly don't have to hurt innocent kids."

Morristown is 280 miles from Pleasant Valley. Shatraw said she has no reason to believe the incident in her town was a copycat of the earlier one.

A handful of cases have been reported across the country since 1991, after a woman in San Diego found 30 razor blades in a sandbox and on other playground equipment.

Suspects in some of the cases were caught. Other cases, like San Diego's, remained unsolved.

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A case in Georgia in 2010 was an exception.

Police in Columbus, Ga., investigated a case after finding box-cutter-type razor blades taped to playground equipment.

Police arrested two men and charged them with criminal damage. Gary Bryan of Columbus was 18 at the time and Derek Fullum of Phenix City, Ala., was 21.

Chief Ricky Boren said in a news release at the time that the suspects claimed they planted the blades as a "practical joke." No one was injured.

Kevin Boehm, a playground inspector in Madison, Wis., said an incident in 1997 in Arlington Heights, Ill., where two preschoolers were injured by razor blades embedded in a slide at public park, prompted changes to his training.

"It's something I always look for," Boehm said. "Typically, we don't look for razor blades that are glued. We look in the seams in slides, especially spiral slides where the sections bolt together."

Police never caught a suspect. Detective Sgt. Rick Kappelman, who was with the Arlington Heights Police Department at the time and remembers the incident, said there hasn't been another one since.

"It was rather isolated," Kappelman said. "We haven't had a repeat incident since."