A Florida woman fatally shot her terminally ill husband at a Daytona Beach hospital on Saturday and then barricaded herself in his room for hours before surrendering, police said.

According to Daytona Beach police, the 76-year-old woman shot her 77-year-old husband in the head. He had been ill for some time, police explained, and the couple had planned the shooting together, KTLA sister station WFLA reports.

“Apparently because he was terminally ill, they had a conversation about it and they actually planned this approximately three weeks ago, that if he continued to take a turn for the worst, he wanted her to end this,” Daytona Beach Police Chief Jakari Young told reporters during a press conference. “Apparently the goal was for him to do it, but he didn’t have the strength, so she had to carry it out for him.”

He said officers deployed a flash-bang device as a distraction in order for them to use “less-lethal” measures to subdue her. The woman did not harm herself and no others were wounded.

“She could be facing a first-degree murder charge,” Young said. “They’re working on the paperwork, but she will be charged.”

As the incident unfolded, Dr. Joshua Horenstein, listed as a cardiologist for AdventHealth, responded to a police department tweet, saying he was locked in a closet during the incident. Police later said the staff and patients were removed from the area, but their efforts were complicated by the fact that most patients on the floor were on ventilators.

No staff or patients were threatened during the incident. The Daytona Beach Police Department is investigating how the woman was able to bring the gun into the hospital.

AdventHealth officials did not immediately respond to requests for comment.

If you are in crisis, you can call the National Suicide Prevention Lifeline anytime at 988 or 1-800-273-TALK.

The Associated Press contributed to this report.