(NewsNation) — A 36-year-old Texas woman who opened fire at Joel Osteen’s Houston megachurch on Sunday before being killed by security officers had a history of mental illness and had written antisemitic messages, police said Monday.

Genesse Ivonne Moreno was shot and killed just before 2 p.m. after exchanging gunfire with two off-duty police offers who were working security at Lakewood Church on Sunday. The shooting also critically injured Moreno’s 7-year-old son, who is “fighting for his life,” Houston police said. The boy was injured after suffered a gunshot wound to the head in the exchange with police.

Moreno was identified in an affidavit seeking a search warrant for a home in Conroe, a north Houston suburb. Police indicated at a news conference Monday afternoon hat Moreno acted alone in carrying out the shooting. A 57-year-old man who was identified in the search warrant as Tom George Thomas., was also wounded in the shooting, but has been released from the hospital, according to authorities.

What happened

Moreno arrived at the church at 1:53 p.m. and got out of a white vehicle. Police said that the took her 7-year-old son and a bag from the vehicle and entered the church after encountering a security officer. Moreno then walked into a hallway and began firing multiple rounds with the AR-57 rifle. Two off-duty police officers who were working security at the church at the time returned fire involving several rounds.

Moreno was struck by the gunfire in the exchange and fell to the ground as did her son, investigators said. Moreno was pronounced dead by Houston Fire Department responders at 2:07 p.m. The boy remains in critical condition.

A sticker with the word “Palestine” written on it was found on the butt of the AR-57, according to Houston Police Commander Christopher Hassig. Hassig added that in addition to the sticker, police have also recovered what they called “antisimitic writings”.

Investigators said on Monday that police have been made aware of family issues between Moreno’s ex-husband and his family members, some of whom are Jewish. Police said that those relationships “may be where all this stems from.”

However. Hassig said police believe that Moreno acted as a “lone wolf” and that they do not believe she is part of a larger organization. Police said that it is too early to determine a motive for the shooting.

Moreno was previously placed under emergency detention orders by Houston Police in 2016 and that she does have a mental health history that has been documented by police and by family members, investigators revealed at the news conference. But it is now believed those struggles may have led to Sunday’s tragedy at the church.

“Unfortunately, we’ve always said that it’s not a matter of if an active shooter event will occur in our city, but when,” FBI special agent Doug Williams said at a news conference. “That ‘when’ was Sunday afternoon just before a service at one of the largest congregations – not just in Houston or Texas -but in the United States.”

Williams said that had it not been for the quick response of the two security officers, the number of casualities and victims would have been “much higher.”

“There is no doubt, there is no doubt that their heroric actions saved lives,” Williams added.

FBI officials on Monday credited the collaboration between law enforcement agencies who responded to Sunday’s active shooter situation. City officials called for local residents to come together as investigatators begin to piece together what may have led to the incident that led to police shooting and killing Moreno.

“Every place of worship is important to the law enforcement community that stands behind me,” Houston Mayor John Whitmire said. “Whether it’s our churches, our synagogues, our mosques, our temples, are going to provid you protection.”

Houston Police Chief Troy Finner said it is important that local residents, regardless of their faith, come together after a scene at the church that police characterized as “hectic”.

“It’s important, as the mayor said, that our communities – and not just our religious institutions – all of our communities – we need to hold one another up in this moment and in any other moment,” Finner said. “We need to watch out for one another.”

Osteen did not attend Monday’s news conference. Police said the pastor is focusing on his congregation as beginning the healing process for his church’s community.

Investigation launched

Prior to being shot and killed, Moreno said that she had a bomb in her possession. Documents show that Moreno was in possession of a yellow-colored rope and substances that are consistent with manufacturing explosive materials. The yellow rope appeared to be a detonation cord, accordingto the search warrant.

However, the search warrant states that at this time, police are unable to determine whether Moreno’s threat of possessing a bomb is credible.

Because Moreno’s crime involved an active shooter scenario at a large church in the Houston area, police believe that it is likely information pertaining to her motive are likely to be found on content stored on Moreno’s devices.

Police, in speaking with Texas Rangers, believe that evidence linked to the crimes of aggravated assault with a deadly weapon, a bomb hoax, or possession of prohibited weapons are likely to be found inside Moreno’s home or vehicle. Police witnessed a white Lincoln MKC registered to Moreno at the church and parking outside Moreno’s home.

Investigators revealed that Moreno has used multiple aliases in the past, using both male and female identities. But an initial investigation determined that Moreno identifies as a woman.

The investigation is expected to take time to come together and city officials called for local residents to pray for those involved, namely Moreno’s son as he continues to fight for his life. The FBI is asking anyone with information about the incident to come forward to provide information that could help provide more insight into the shooting.

“When the sanctity of a church is violated – or any house of worship – that is an attack on the very foundation of this nation,” said Kevin Lilly, the director of the Texas Alcoholic Beverage Commission’s Houston Division.