75-Year-Old Man, a Former Police Officer, Admits to Random Knife Attack on Woman in Pasadena

A 75-year-old former U.S. Marine and Pasadena police officer pleaded no contest Wednesday to an attempted murder charge for slashing the throat of a woman during an unprovoked and seemingly random attack in Pasadena, officials said.

As the result of a plea arrangement, Robert Anthony Semkus of Pasadena is expected to be sentenced to seven years to life in state prison when he returns to Los Angeles Superior Court on July 13, according to the Los Angeles County District Attorney’ Office.

In addition to the attempted murder charge, Semkus also admitted to the special allegation that he used a knife in the crime, District Attorney’s Office Spokesman Ricardo Santiago said in a written statement. Additional charges of attempted robbery, mayhem, and two counts of cruelty to animals were dropped.

The stabbing took place on the afternoon of Oct. 23, 2017, in the 600 block of South Arroyo Parkway. Semkus approached the victim and slashed her throat without any apparent reason, police said at the time.

Semkus was arrested later the same day.

He had also been charged with attempting to rob a woman of her dog in front of a Pasadena pet store about an hour before the stabbing, as well as killing his own two dogs, which were found dead at his home, officials said. Charges connected to those allegations were dropped under the plea arrangement, along with a count of mayhem, which is legally defined as depriving someone of a part of their body or disabling them.

Semkus served in the U.S. Marine Corps from 1962 to 1966, according to federal records. He served as a police officer in Pasadena from 1967 to 1971, then worked as a Burbank police officer from 1974 to 1977, Pasadena and Burbank city officials said.

If he had been convicted as originally charged, Semkus could have faced up to 32 years to life in state prison.