A Pleasanton man who confessed to stabbing his mother multiple times after turning himself in to police two weeks ago says he did so "quickly" and "humanely," after he had finally had it with her nagging.

31-year-old Malcolm Tilley was arrested April 1 on suspicion of the murder of his mother, 71-year-old Marjory Methvin Tilley, after he walked into the Pleasanton Police Department headquarters and confessed to the crime.

Tilley directed police to the home he shared with his mother, on the 4000 block of Alvarado Street, where they found Methvin Tilley lying dead in a pool of blood, surrounded by three kitchen knives.

As Bay Area News Group reports*, via court documents, Tilley returned from a trip to Safeway on April 1, and spontaneously decided to end his mother's life, using two knives — one of which broke, prompting him to fetch a third knife. He claimed that he committed the killing "humanely" and "quickly" so that his mother would not suffer, but police say the crime scene suggests otherwise.

"In Tilley’s confession to police, he reportedly blamed his aggression on his mother’s belittling, saying that she had a problem with his current 'financial' and 'employment,' status, that she challenged his 'masculinity,' his 'looks,' and his 'worthiness to exist,'" reports Bay Area News Group via police statements. Tilley also  reportedly said "the nagging had lasted his entire life."

After the stabbing, Tilley told police he took a shower and left his bloody clothes on the floor of the bathroom. And, he said in his confession, according to police, he didn't clean up any of the crime scene because he "decided that would make his actions look suspicious."

Tilley has been charged with murder with the special circumstance of aggravation, and with use of a deadly weapon. He is being held without bail, and is scheduled to be arraigned April 23.

Pleasanton Weekly reports that Marjory Methvin Tilley had been a volunteer senior service provider at the Pleasanton Senior Center for over three decades, and coworkers there expressed shock at the crime. Malcom was reportedly her only child, and Tilley's husband died years ago.

The case is reminiscent of another case in the East Bay from October, in which a 46-year-old man living with his mother and half-brother is suspected of murdering them both.

*The Bay Area News Group report appears to have misprinted the accused's name as Marcus Tilley.