A South Pasadena man pleaded guilty Tuesday to killing his 5-year-old son after a family trip to Disneyland earlier this year.

Aramazd Andressian Sr., 35, pleaded guilty to one count of first-degree murder in the death of Aramazd Andressian Jr. during a hearing at the Los Angeles Superior Court in Alhambra. He had previously pleaded not guilty to the charge. He will face 25 years to life in prison when he is scheduled to be sentenced Aug. 23.

Andressian Sr.s made an open plea, meaning it was not negotiated with the Los Angeles County District Attorneys Office. He showed little emotion during the hearing. Andressian Jr.'s mother, Ana Estevez, was in court Tuesday, along with several other family members.

Andressian Sr.'s attorney told reporters Tuesday that following his client's arrest in Las Vegas, he provided investigators with the information that led them to Andressian Jr.'s body.

Today, Mr. Andressian took responsibility for what he did and he has pleaded guilty to first-degree murder, Andressian Sr.s attorney Ambrosio Rodriquez said. It was Mr. Andressian, when he was brought back to Las Vegas, that gave the officers the information as to where his son was buried.

Prosecutors contend Andressian Sr. killed his son, Aramazd Andressian Jr., to get back at his estranged wife.

Los Angeles County sheriffs investigators have said they think the boy was killed early April 21. His body was found on June 30 near Lake Cachuma in Santa Barbara County, the same day Andressian Sr. was extradited back to Los Angeles.

Andressian Sr. was found passed out in a South Pasadena Park on April 22. He had taken prescription pills and was found in a car doused in gasoline in an apparent suicide attempt, sheriffs officials said. Andressian told authorities that he drove that day about 145 miles to Lake Cachuma.