BAKERSFIELD, Calif. (KGET) — Arrested in the death of his wife, Nathaniel Robertson admitted during an interview with sheriff’s detectives to beating her with a concrete block.

But Robertson, in a confusing, rambling statement, said he did it to “give her compassion and mercy” as “the alignments were not in place to protect her,” according to recently released court documents.

He said he had been infected by mayonnaise “they” put in him, the documents say. The “they” in this case was a group of “brutal, powerful” people Robertson said he couldn’t identify.

There was something inside him releasing information from the Revolutionary War, Robertson told investigators. Asked if he used drugs, he said he used “ice” to help him breathe.

Ice is commonly used to refer to methamphetamine. Robertson also said he’d been ingesting “crystal,” which a detective understood to mean crystal meth, the documents say.

Robertson said he loved his wife and she was his best friend.

“I didn’t want it to be a painful thing,” Robertson told investigators. “I didn’t want to hit her a bunch of times, I wanted to end it, I didn’t want her suffering.”

Robertson, 46, has pleaded not guilty to a charge of first-degree murder in the death of Lidia Robertson, 57. He’s held on $1 million bail.

Deputies dispatched to a residence in the 300 block of Sycamore Drive the morning of July 11 found blood spattered across the floor at the front entrance.

Lidia Robertson was lying on the floor with “major head trauma” and a large pool of blood surrounding her, the documents say. A large concrete block was next to her.

A neighbor told deputies she heard arguing coming from the Robertsons’ residence the night before. The neighbor said she saw Nathaniel Robertson leave the residence and later return carrying what she described as a large rock.

Nathaniel Robertson again left his residence around 1:30 a.m. and walked toward Riverview Park, the neighbor told deputies.

Another person said Nathaniel Robertson suffered from mental illness and abused drugs, and he and Lidia Robertson had remained married only for financial reasons, the documents say.

Deputies arrested Nathaniel Robertson at the park. He said he had been walking around looking for a place to kill himself, according to the documents.