A state appeals court panel on Tuesday upheld a Long Beach man’s conviction for killing his neighbor three years ago.

Mark Thurwachter’s conviction for the February 1, 2012 killing of 60-year-old Marvin Williams was denied reduction to second-degree murder by the three-justice panel from California’s 2nd District Court of Appeal.

The appelate court justices stated in an eight-page ruling that there was “substantial evidence upon which the jury could have reasonably rested its first-degree murder finding.”

“As for planning and deliberation, defendant’s numerous threats to kill Mr. Williams were circumstantial evidence of a preconceived plan to kill Mr. Williams when the time was right,” the panel noted.

Neighbors at Arbor Mobile Village told police that Thurwachter had a long-standing dispute with Williams, who was shot once in the chest outside his residence.

Thurwachter never returned to his home, and an arrest warrant was issued five days later. He was arrested in March 2012 in Cleveland during a fare evasion investigation conducted by the Greater Cleveland Regional Transit Authority and was returned to Los Angeles County for trial.

Thurwachter was convicted in February 2014 and sentenced to 50 years and eight months to life in state prison.

City News Service contributed to this report.