By Nicole Chavez, CNN

(CNN) -- Devin Kelley walked into a Texas church turning joyous prayers into screams of terror as he killed more than 20 people.

Four days after the shooting, investigators continue looking into Kelley's past and motive as people in the small town of Sutherland Springs are trying to cope with the tragedy.

At least 10 people who survived the carnage remain hospitalized in critical condition. Other survivors along with members of this close-knit community comforted each other and gathered at a memorial of crosses near the First Baptist Church.

"It was something that I don't want to think about anymore," said Rosanne Solis, one of the worshipers who survived the shooting. "It's always going to be there."

Kelley carried out the deadliest mass shooting in Texas history on Sunday, but records show his violent behavior could have begun years ago.

Latest developments

• Kelley escaped from a New Mexico mental health facility in 2012 after sneaking guns onto an Air Force base and making threats against commanders, according to a police report.
• The FBI has the shooter's cellphone, but has not yet accessed its content due to encryption, said Christopher Combs, FBI special agent in charge.
• Husband and wife, Robert and Karen Marshall, were among the 25 people -- and an unborn child -- killed Sunday during the Texas shooting, family members told CNN affiliates WTAE and KDKA.
• Vice President Mike Pence and his wife, Karen, will travel to Sutherland Springs on Wednesday to meet with victims' families, he tweeted.

Warning signs

Kelley had a troubled past and was prone to domestic violence and animal cruelty, according to public records and those who knew him.

During his time in the Air Force, Kelley was involved in "multiple occasions of domestic abuse" against his ex-wife and stepson, said Don Christensen, a retired Air Force colonel.

Kelley was placed into pretrial confinement at a civilian facility in New Mexico to wait for his court martial in 2012 but he managed to escape days later, according to documents from the El Paso Police Department obtained by CNN affiliate KVIA and two Air Force officials.

When officers were called to find Kelley, they were warned that he was a danger to himself and others and that he had sneaked firearms onto Holloman Air Force Base. He had reportedly threatened his commanders, the documents said.

He was ultimately discharged after he pleaded guilty to assault charges, admitting he hit his then-wife and stepson, officials said.

After his release in 2014, he landed in El Paso County, Colorado, where he was arrested on an animal cruelty charge. A neighbor told police he saw Kelley punching a dog, grabbing it by the neck and then dragging the animal. Kelley denied the account and was issued a summons but didn't spend any time in jail.

Kelley's social media suggested a fascination with mass shootings, a law enforcement official said.

He spent time posting anti-God and pro-gun statements, said Christopher Leo Longoria, who attended high school with Kelley.

Longoria described Kelley's Facebook posts as "a ridiculous amount of nonsense." Kelley's page has been taken down but people in the community have confirmed its existence and content.

Kelley had previously attended the Texas church but he was not welcomed there, Wilson County Sheriff Joe Tackitt told CNN on Tuesday.

Pastor Frank Pomeroy of First Baptist Church knew Kelley from his attendance at church events, according to Tackitt. The pastor wanted him out.

There were no threats but Pomeroy told authorities Kelley "was not a good person to be around."

"He did not think that he was a good person and did not want him around his church," Tackitt said of the pastor. "But he said, 'How do I run him away from my church?'"

Families remember the victims

As authorities have yet officially identified the victims of Sunday's shooting, families and close friends are sharing the stories of the victims.

Husband and wife Robert and Karen Marshall had recently moved to Texas from Pennsylvania and were visiting the church for the first time when the shooting took place.

Robert Scott Marshall -- who goes by Scott, according to his sister, Holly Hannum "was a great guy."

"He would have given you the shirt off his back and would've helped you do anything," Hannum told CNN affiliate WTAE.

He was a veteran, and Karen was also in the service. She was planning on retiring, Scott's father, Robert Marshall, told CNN affiliate KDKA. He added that his son worked on engines.

Just feet away from the First Baptist Church in Sutherland Springs, 26 white crosses honoring the victims stand surrounded by American flags, balloons and flowers.

Judy Green, a Sutherland Springs resident and member of the church, brought pink roses for the victims. For her, many of them were family, including 14-year-old Annabelle Pomeroy.

"I know Annabelle loved roses in rose color and purple. I don't have words for my loss for her, loss for everyone," Green told CNN affiliate KSAT.

"She's been our little baby. We all raised her in the church. She's been special," Green's husband Rod said.