FORT WORTH, Texas -- It was a moment that John Winkler had been anticipating for more than two years.

"When I saw her mugshot, I felt a little sorry for her, I did," he says. "But we need justice."

Jessica Langlais, 31, was arrested Monday for the killing of little Adrian Langlais in March of 2015.

While her then boyfriend, Christian Tyrrell, was arrested shortly after Adrian's death, Jessica remained free.

Winkler, who considered himself a caretaker for the boy when Jessica had dated his then stepson, says red flags of abuse were there before Adrian's death.

"There were fingerprints on the body, big hand prints on the leg, a knot on the head," he said.

He alerted Child Protective Services, but the boy remained in his mother's care.

Winkler remembers well that day in March when he heard Adrian had been rushed to the hospital with traumatic head injuries.

"There was only two people. She needs to answer as to what her involvement is in this," he says.

At the time, the couple offered varying accounts of what happened, but court documents related to Tyrrell's case indicated at least he was aware the child was suffering. Phone records showed an Internet search had been done for “how to tell if someone has went brain-dead,” 14 hours before 911 was called.

Winkler says he recently met with the Tarrant County Attorney's Office investigator and "sensed" they might be moving on a case against Jessica, although he said specifics weren't discussed.

A district attorney spokeswoman declined to comment on why an arrest took two years, citing the fact that Tyrrell's trial is set for later this summer.

Winkler says he's just glad investigators didn't forget about the larger case. He still regularly visits Adrian's grave site.

"It's tough. You see this beautiful child that you can't touch anymore, or talk to anymore," Winkler said.