CHICAGO (CBS) — The huge police response at Millennium Park last weekend for what was first thought to be a bomb, but was not, cost the city thousands of dollars.

Now, as WBBM Newsradio 780’s Steve Miller reports, the city might try to get its money back.

LISTEN: Newsradio 780’s Steve Miller reports

The object that cleared part of Millennium Park this past Saturday night was not a bomb, of course. The teenager from the Old Town neighborhood who was arrested and charged with misdemeanor disorderly conduct told Newsradio 780 it was a “little doohickey” with wires he had made to go with a costume he had worn for a cosplay event.

Now Jennifer Hoyle, spokeswoman for the city law department, says departments that responded Saturday night are totaling the cost of that response.

And then, she says, “The law department will work with them to determine what legal action is appropriate.”

Hoyle says it is the city’s practice to file a cost recovery action in cases like this.

The device, which had batteries and wires coming out of it, was found near the Cloud Gate sculpture, better known as “The Bean” in Millennium Park. Part of the park, including the Park Grill, was evacuated at the busy hour of 5:30 p.m.

But the object turned out to be two bricks wrapped in duct tape.

The teen, Emmett DeFrisco of the 1600 block of North Vine Street, said he was taking part in Soycon, billed as the largest cosplay gathering in the Midwest.

“Me and my friends were coming back from an activity where we dress up and act as our favorite characters, and I was dressed up as a Doctor Who character. It’s a BBC show,” he said.

It’s not clear how much the city could recover in this case, since DeFrisco is only 18.