'Daddy, I'm Sorry,' 8-Year-Old Said Before Father Allegedly Slit His Throat and Killed Sister

Authorities believe a tearful 8-year-old Texas boy pleaded for his life on Saturday only moments before he and his sister were killed by their father, who then called his estranged wife about a “present” he’d left her at his Houston apartment.

Soon after receiving the disturbing call from her husband, 62-year-old Jean Pierre Ndossoka, Sabine Ntongo drove to his home and discovered the bodies of her two children, court documents obtained by PEOPLE confirm.

Her son, Marcel Ndossoka, and his 1-year-old sister, Anna-Belle Faith Ndossoka, both had their throats slashed, according to investigators.

Police said they took Ndossoka into custody in nearby Pasadena, Texas, on Sunday after finding him in his car seriously injured from an attempted suicide.

Ndossoka is expected to make a full recovery and is already out of the hospital. He has been charged with two counts of capital murder but has not pleaded.

He does not have an attorney of record and is being held without bond.

Investigators alleged in the court documents that Ndossoka told detectives he went ahead with the killings despite the cries of his two children.

After the slayings, he allegedly called Ntongo to admit what he’d done

Authorities said he told his estranged wife where she could locate a spare key to his apartment so that, inside, she would find a “present” he had left her, according to the court documents.

Police translated a note found at the scene that was written in French in which Ndossoka allegedly expressed suicidal thoughts.

Court documents show that, in part of the missive, he allegedly wrote that his wife would have to “carry the burden of our souls” the rest of her life.

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Authorities also recovered the bloody knife they say was used to kill Anna-Belle Faith and Marcel.

The court documents allege Ndossoka initially denied have any memory of the killings. Eventually, however, police say he recanted — telling them he “did something bad.”

PEOPLE was unable to reach Ntongo for comment.