A Pennsylvania man has been charged with the murder of a 4-year-old girl, a crime her 8-year-old brother helped solve, the Philadelphia Inquirer reports.

Authorities on Friday arrested 32-year-old Marquis Lamont Thomas of Hatfield, Pennsylvania, in connection with the 2016 death of Kailee Bunrout, his girlfriend’s 4-year-old daughter.

About one month before she died, Bunrout was reportedly hospitalized with numerous injuries: she had rib fractures that were healing, scars on her torso, a bruise under an eye and burst blood vessels in her eyes.

Police reopened their investigation into the death after her 8-year-old brother in September was hospitalized for many of the same injuries, including bruising under an eye and bleeding in both of his eyes, according to the newspaper.

Investigators in February interviewed the brother, who reportedly said Thomas choked him repeatedly by putting his arm around the boy’s neck and pushing his face into a couch. At the time, prosecutors charged Thomas with strangulation, child endangerment and assault.

More charges were added Friday related to the 4-year-old’s death, including first- and third-degree murder.

“In these cases, when they are hurt by someone they know and trust, it’s very difficult for them to disclose that someone they love has hurt them,” Montgomery County District Attorney Kevin R. Steele told the Philadelphia Inquirer. “Thankfully, the boy bravely shared that information and Marquis Thomas is now being held accountable for the death of 4-year-old Kailee, and the physical abuse endured by her brother.”

In October 2016, emergency crews responded to an apartment complex after Bunrout’s mother called 911; they found Thomas attempting CPR on the girl, who lacked a pulse.

She was rushed to a hospital but was soon pronounced dead.

Thomas reportedly told police that day that he awoke around 7:45 a.m., found the girl in her bed and that she felt cold when he touched her.

He said he then texted his girlfriend that the child wouldn’t wake up; the girlfriend quickly came home and called 911 because Thomas hadn’t done so yet.

Thomas was in jail Friday and had been there since February when he was arrested for assaulting the 8-year-old boy.

He has a preliminary hearing scheduled for next month.

Hatfield is about 30 miles northwest of Philadelphia.