Prosecutors recommended in court papers that the Herndon man who shot a security guard at the Family Research Council be sentenced to 45 years in prison.

Floyd Lee Corkins II went to the conservative organization's Chinatown-area headquarters on Aug. 15 with the intention of killing as many people as he could, according to court documents. But his plan to commit mass violence was thwarted by Leonardo Johnson, a security guard shot by Corkins.

Corkins pleaded guilty in February to three charges, including committing an act of terrorism while armed. He is scheduled to be sentenced in D.C. federal court on April 29.

But the defense on Monday asked the court to postpone sentencing. Lawyers for Corkins wrote that they have not received and reviewed the mental-health records of their client, who was receiving treatment at the time of the shooting. The defense argued that Corkins' mental-health history is relevant to his sentence.

On the day of the attack, Corkins encountered Johnson, the security guard, in the Family Research Center's lobby. Corkins pulled a gun and was pointing it at the guard when Johnson charged Corkins. Johnson was shot in the arm during the struggle. Though injured, Johnson wrestled the gun away from Corkins and subdued him until D.C. police arrived, according to court documents.

Following his arrest, Corkins told FBI agents that he had planned to kill as many people as possible at the research center and smear Chick-fil-A sandwiches in their faces, court documents stated. He said that he wanted to commit these acts to make a statement against the research center employees because the organization opposes gay marriage. Not long before the incident, Chick-fil-A's president had made headlines by speaking out against same-sex marriage.

Corkins also admitted to methodically planning his scheme. He purchased a gun the week before the incident and received firearms training the night before the shooting. Two days before the attack, he had been watching the research center, according to court documents.

Prosecutors wrote in a memo filed on Friday that a 45-year sentence would "appropriately punish the defendant for his actions, keep the community safe from him for the foreseeable future, and deter other would-be domestic terrorists and mass murderers from doing the same."

The government's sentencing memo cited statements from Johnson, who still needs medical attention because of his wound, and from other research council employees who were traumatized by the incident.