Police in Houston, Texas have identified the shooter who opened fire at Joel Osteen's Lakewood Church on Sunday as Genesse Ivonne Moreno, Fox News has confirmed.

Moreno, who has a lengthy criminal record and was born as a man – Jeffrey Escalante – from in El Salvador, was killed after off-duty police officers at the church responded to the incident. 

A search warrant said Moreno pointed an AR-15 at the officers who then fired upon her and killed her in self-defense.

The message "Free Palestine" also was written on the rifle used in the attack, investigators said.

LAKEWOOD CHURCH SHOOTING: FBI, POLICE REPORTEDLY SEARCH HOUSTON-AREA HOME LINKED TO SHOOTER

As a man, the 36-year-old Moreno has a criminal history including convictions for assaulting a police officer in 2009 and forgery in 2010. 

Houston's mayor, its police department and other agencies are scheduled to hold a news briefing at 1:30 p.m. local time.

Members of the FBI, the Texas Rangers, the Montgomery County Sheriff’s Office and the Conroe and Houston Police Departments, were investigating a property Monday in Conroe, north of Houston, that is believed to be Moreno's residence, according to KPRC. 

The shooting happened Sunday afternoon before the Houston megachurch's 2 p.m. Spanish service was set to begin.

Moreno entered the church with a long rifle, wearing a backpack and a trench coat and accompanied by a 5-year-old child, Houston Police Chief Troy Finner said.

WOMAN WITH CHILD IN TOW OPENS FIRE INSIDE JOEL OSTEEN'S HOUSTON MEGACHURCH

After the shooter opened fire, off-duty officers at the scene "engaged" the shooter and returned fire. Moreno was pronounced dead at the scene.  

Police said that two people were injured – a 57-year-old man and the child that who the shooter came with, who remains in critical condition at a children’s hospital. The child is not expected to survive, a Montgomery County District Attorney's Office spokesperson told the Houston Chronicle.

During a press conference, Osteen thanked law enforcement and said that he was "devastated" by the shooting.  

"We don't understand why all these things happened, but we know God's in control," Osteen said. 

Texas Gov. Greg Abbott called the shooting "tragic." 

The motive for the shooting is unclear.

Fox News’ Andrea Vacchiano contributed to this report.