LONDON (AP) — The partner of British children's author Helen Bailey has been convicted of killing her and dumping her body in a cesspool in a financially motivated murder.

A jury on Wednesday found Ian Stewart guilty of murder, fraud, perverting the course of justice and preventing a lawful burial.

The body of 51-year-old Bailey was found in a cesspool at the home she shared with Stewart in July, three months after she was reported missing.

Prosecutors said Stewart drugged Bailey and likely smothered her when she was unconscious to gain her 3.3 million-pound ($4.1 million) estate. He will be sentenced Thursday.

Bailey created the Electra Brown and Daisy Davenport novels for teenagers, and wrote a blog called Planet Grief after her husband of 22 years drowned during a Caribbean holiday in 2011.