A 20-year-old pastor's daughter was critically injured Sunday after she was accidentally shot while attending church services at the Grace Connection Church in  St. Petersburg, Fla., according to authorities.

Moises Zambrana, 48, a church congregation member, accidentally discharged his gun and the bullet struck Hannah Kelley in the head.

After the shooting, Kelley was transferred to a  local hospital, where she remains in critical condition after undergoing surgery.

Ceclia Barreda, the public information specalist at the Pinellas County's Sheriff's Office, told ABC News.com  that Zambrana was showing off his 9mm handgun to Dustin Bueller, Kelley's boyfriend, and another congregation member, when the  gun went off.

"They're all known to each other," said Barreda of the three men. "[Bueller] was going to be turning 21 soon and was planning on to buy a gun of his own."

According to Pinellas County's Sheriff's Office, Zambrana, who had removed the gun's magazine, was explaining the gun's safety features when it discharged.

The case remains under investigation, but no charges have been filed against Zambrana, who had a license to carry a concealed fire arm.

While the Kelley family could not be reached for comment,  Tim Kelley, Grace Connection's pastor, posted a message on the church's Facebook wall. After describing his daughter's condition as "very critical" and her prognosis as "not very good," Kelley  thanked his congregation for its support.

"The outpouring of love has been overwhelming and humbling - thank you all,"  Kellywrote . "Please continue to pray for my family. We  need a miracle."