In this image taken from body camera video released by the Houston Police Department, officers respond after exchanging gunfire with a woman who opened fire at celebrity pastor Joel Osteen’s Houston megachurch. AP

The gunfire that shattered the calm at pastor Joel Osteen’s megachurch in Houston only lasted about four minutes. But surveillance video and police body camera footage released on Monday, more than two weeks after the Feb.11 shooting at Lakewood Church, showed the terror of the brief attack: Parishioners scattering, searching for safety in rooms and hallways.

Officers drawing guns and taking cover behind walls. And the shooter's 7-year-old son covering his ears during the chaos, and moments later laying on the floor after being shot and wounded.

"Put the weapon down, now,” an officer can be heard shouting before firing his weapon. Another officer cautions: "She may have a bomb.”

Houston police released the roughly 26 minutes of video, which includes the sounds of dozens of bursts of gunfire, as questions remain over the attack that left the shooter, Genesse Moreno, 36, dead and two others injured. Authorities have still not released a motive for the shooting or confirmed who shot Moreno's young son in the head. He remains in critical condition.

Authorities say the woman entered the church between Sunday services and began firing an AR-style rifle. Moreno did not reach the main sanctuary and was killed after exchanging gunfire with two off-duty officers. In addition to Moreno's son, another man was wounded.

The video shows what looked like, from all appearances, a typical Sunday at one of the nation's largest megachurches as people stood around and talked in the hallways outside the nearly 16,000-seat venue.

Minutes earlier, according to security footage from Lakewood Church, Moreno had arrived at the church in a white SUV. She is seen taking her son, Samuel, out of the back seat and walking towards the building. Moreno is wearing a black shirt, striped pants, boots, and a loose-fitting tan-coloured trench coat.

Footage from one body camera showed people chatting before suddenly jolting at the sound of the first gunshot. Confused, some began running and then rapid gunfire ensued. Bystanders could be seen taking cover in rooms and hallways.

Off-duty police officers, crouching with handguns out, could be seen as they ran toward the sound of shots being fired.

As one officer moved towards the gunshots with another officer, she said, "We need to approach. Father God, just be with us. Forgive us our sins.”

In the video footage, gunshots could be heard ringing throughout the church building as officers closed in on the source of the shooting.

Additional security video from the church, which didn’t have sound, showed the boy, who appeared to be in a recessed doorway, covering his ears after his mother walked off screen. She then came near him and he reached his arms out to her. When she walks off screen again, the boy appears to follow her.

In the footage, Moreno could be heard saying, "you killed my son.” She later said, "Stand down, I have a bomb. I have a (expletive) bomb.” Gunfire could be heard as she talked. Houston police have not said who fired the shots that wounded the boy.

In another part of the church, Moreno walked down a hallway, pointing her AR-style rifle. Within two minutes, she was shot multiple times before she collapsed to the ground and was approached by officers, the security security footage shows.

Later, an officer reported over the radio, "Shooter is down. Looks like she’s got something strapped to her chest.” Another officer requested the bomb squad. Authorities later said no explosives were found.

From the time the shooting first began, to when officers said that Moreno had been fatally shot, about four minutes had passed, according to the released footage.

Associated Press