TAMPA — The government wants to publicly conceal the identity of a key witness against Sami Osmakac, the 26-year-old Pinellas Park man accused of trying to obtain explosives and guns to attack Tampa targets.

In its filing this week in federal court, prosecutors say that making public the true identity of the undercover FBI agent they say met with Osmakac in 2011 and 2012 and supplied him with fake weapons would jeopardize other investigations and endanger the safety of the agent and his family.

"These conclusions are not idle speculation," asserts an affidavit from R.J. Holley, an FBI counterterrorism official. "…With the simple click of a mouse, personally identifying information about or a photograph of (an undercover agent) — like the valuable law enforcement officer in this case — can be transmitted instantly to adversaries."

The government said that defense attorneys agreed with most but not all of the measures. If approved by a judge, they would include among others:

• Using the agent's pseudonym in testimony;

• Prohibiting the defense from asking questions that may reveal his identify;

• Allowing the agent to appear in court in "light disguise," such as changing his hairstyle;

• Banning the public from the courtroom during his testimony, allowing only the jury and "essential personnel" inside. A video feed, not showing the agent's face, would be made available to the public in some other room in the courthouse.

Osmakac is accused of trying to buy guns and explosives, including a car bomb, to destroy targets in Tampa, including a Hillsborough County Sheriff's Office operations center and a South Tampa nightclub. He is being held in jail without bail.

His trial is scheduled to start Oct. 21 in Tampa federal court.