A week after a crazed 23-year-old shot and killed two children and injured 18 more victims at a Catholic mass in Minneapolis, details about a chaotic personal life and a meticulously planned attack by a maniac who was "obsessed with the idea of killing children" have begun to unravel.  

Robin Westman, formerly Robert Westman, committed the heinous act at the Annunciation Catholic Church the morning of Aug. 27 before committing suicide at the scene. As a child, Westman attended both the school and the church, which is located next door.

The years and months leading up to the unthinkable mass shooting appear fraught with chaos in the shooter's personal life. 

MINNEAPOLIS POLICE REVEAL MORE ABOUT CHURCH SCHOOL SHOOTER'S MOTIVE

Court records show that Mary Grace Westman and her ex-husband, James Westman, divorced in 2012. Robin, then Robert, was 11 at the time and had two older siblings.

The custody agreement showed Mary Grace as his primary caretaker, with his father given custody every other weekend. 

Both parents had Minneapolis addresses until at least 2021. 

Citing police records, NBC reported that local police responded to a "criminal offense" at the suburban Westman home. Further details are scant, but the case was closed. 

Two years later, police in Eagan, Minnesota were called to the home, this time for an incident described only as "mental health." 

The incident report noted that Eagan police "assisted Mendota Heights with a check welfare of a juvenile," according to NBC. 

It is unclear who the juvenile in need of a mental health check was. 

Robert Westman became Robin Westman in 2019. 

Westman's mother, Mary Grace Westman, signed off on the name change. 

Court documents show the shooter’s mother applied for her son to legally change his name, writing in 2019, "minor identifies as female and wants her name to reflect the identification."

MINNEAPOLIS CHURCH SHOOTER ROBIN WESTMAN'S FORMER CLASSMATE SAYS SHE KNEW SOMETHING ‘WAS OFF'

Minneapolis Police Chief Brian O'Hara confirmed that the shooter's mother worked at the school for several years, and retired in 2021. 

According to a warrant, James Westman told police that Westman had "recently" broken up with a romantic partner. 

In that same warrant, the elder Westman told police that the shooter moved in with a friend at the St. Louis Park address that police searched after the shooting.

Neighbors speculated that Westman could have moved into the new location just two weeks prior to the shooting, while some said he moved in earlier this summer. 

Westman visited the church in the weeks leading up to the shooting in order to "scout" the location, CNN reported. He had interactions with people there, and told them he was trying to reconnect with his faith. 

The soon-to-be mass killer may have been to the location more than once leading up to the attack, according to journal writings analyzed by The New York Post. 

According to the Minnesota Star Tribune, Westman left his job at a marijuana dispensary called RISE only 11 days before the shooting. 

An unnamed coworker told the paper that he worked as a "personal care specialist" and worked with patients who were part of a state medical marijuana program. 

That coworker cryptically said "recent events have been the catalyst for this thing he has been planning for a long time."

RISE said in a statement that it was "deeply saddened" by the shooting, and offered condolences to the victims, their families and the community as a whole. 

"We have been informed that the individual identified by authorities as the shooter was a former employee of our RISE Dispensary in Minnesota for several months this year," the company said. This individual was not employed by the company at the time of the incident."

The company said it is fully cooperating with investigators. 

The day before the shooting, the Collier County Sheriff's Office responded to a juvenile welfare check at Mary Grace Westman's Naples, Florida condo. 

Deputies were looking for a child and the child's mother who they say previously lived with Westman at the home.  

"Contact was made with Mrs. Westman who stated the juvenile and the juvenile’s mother had previously lived there and were no longer living with her," the Collier County Sheriff's Office told Fox News Digital. 

"Deputies later contacted the mother of the juvenile and confirmed the juvenile was okay. This call for service was not related to the incident in Minneapolis or the shooter."

GUNS USED BY MINNEAPOLIS CHURCH SCHOOL SHOOTER ROBIN WESTMAN WERE PURCHASED LEGALLY, POLICE SAY

Westman opened fire from outside the church just before 8:30 a.m. and fired more than 100 rounds, killing two and injuring eighteen others, including 15 children. The shooter wore all black and was found in possession of four firearms. 

The doors to the church were locked before mass began, which police said "likely saved countless lives." 

Police arrived on the scene within minutes, and by 9:00 a.m., announced that there was no further threat.

8‑year‑old Fletcher Merkel and 10‑year‑old Harper Moyski were later identified as the deceased victims. 

Later in the day, a search warrant was executed at a St. Louis Park residence where Westman had been staying with a romantic partner until a recent breakup. 

Police also made contact with James Westman, the shooter's father, who confirmed that the shooter drove a minivan police found at the scene.

The FBI arrived at the Naples condo in the afternoon, though she was not home when agents arrived, according to WINK. 

GRIEVING FATHER CALLS MINNEAPOLIS SHOOTER A 'COWARD' WHO TOOK LIFE OF HIS 8-YEAR-OLD SON FLETCHER DURING MASS 

Mary Grace Westman has refused to cooperate with police in the wake of the attack, and has hired an attorney. 

"She is completely distraught about the situation and has no culpability but is seeking an attorney to deal with calls like this," attorney Ryan Garry told Fox News. 

While the shooter's exact motive remains unknown, Acting United States Attorney for the District of Minnesota Joe Thompson said hatred aimed at everyone played a significant role. 

"The shooter expressed hate towards almost every group imaginable. The shooter expressed hate towards Black people. The shooter expressed hate towards Mexican people. The shooter expressed hate towards Christian people. The shooter expressed hate towards Jewish people," Thompson continued. "In short, the shooter appeared to hate all of us. The shooter's heart was full of hate. There appears to be only one group that the shooter didn't hate. One group of people who the shooter admired. That group were the school shooters and mass murderers that are notorious in this country." 

The FBI is investigating the mass shooting as a hate crime. 

Mary Grace Westman did not return a comment request. 

Fox News' Michael Dorgan, Greg Wehner, Brooke Taylor, Stephanie Price and Greg Norman contributed to this report.