A loud crack from the courthouse doors set Johnson County Sheriff’s Deputy Sue Henderson in motion. She leapt from her desk, dashed around the corner, and gazed down the stairs to the main entrance of the Johnson County Courthouse.

Nothing suspicious.

Henderson is one of two deputies assigned to the courthouse who act as daily security guards. Aside from a system of cameras, the deputies’ presence is the extent of security throughout the building, she said.

“We do the best we can for what we have to work with,” Henderson said, returning to her desk.

A number of local officials, including Henderson and Johnson County Sheriff Lonny Pulkrabek, said increased security at the courthouse is needed. But Pulkrabek said the current set-up will have to do until a new justice center is built.

Henderson said the existing measures are insufficient, and she’d like to see metal detectors and additional security staff deployed at the courthouse.

The Polk County Courthouse employs metal detectors, baggage screens, and security cameras, said Capt. Greg Peterman of the Polk County Sheriff’s Office. He said he was surprised officials weren’t using similar measures in Johnson County.

“For a county of that size, I think that they should have more security,” he said. “I’m surprised that they don’t.”

But while local officials said they want more security, Pulkrabek acknowledged the future Justice Center would alleviate many of the concerns. And for now, they must contend with the current building’s layout.

The rear, handicap-accessible entrance is too narrow for a security checkpoint, and the larger front entrance leads directly into a pair of stairways.

“I think more [security] is needed,” Pulkrabek said. “But there has to be some significant structural changes before that can come about.”

During high-profile cases, a metal detector can be placed at a single entrance, or at the doorway to a courtroom. But Pulkrabek said it’s not possible to make these measures a part of regular security.

“The design of the courthouse lacks for it,” he said. “There’s no way without spending an enormous amount of money remodeling to funnel everyone through one entrance.”

The new Justice Center, which county officials have discussed since the early 2000s, would address the security and space needs of the courthouse by funneling all visitors through a single secure entrance and adding additional offices and courtrooms as well, Pulkrabek said.

Johnson County Supervisor Rod Sullivan said the justice center, which would include a renovated courthouse and jail, will cost between $50 million and $54 million. Sullivan said the Criminal Justice Coordinating Committee met Jan. 5 to reaffirm past plans, which placed the new center in the area near the current jail, 511 S. Capitol St.

Sullivan said he expects the supervisors to present a referendum on the subject sometime in 2012.

Maj. Michael Brown of the Scott County Sheriff’s Office said his county’s new courthouse — built three years ago — funnels visitors through one main entrance, complete with metal detectors, baggage scanners, security cameras, and uniformed bailiffs. Officials have disallowed cell-phone use inside the building.

The new security measures have detected knives and guns on occasion, Brown said, but he’s unsure just how much security is “too much.”

“It’s hard to say,” he said. “What is it that makes a building unsafe?”