There’s been an art heist at the Sam Simon Foundation in Malibu, California, and police are hunting for two paintings—one by American Pop artist Roy Lichtenstein—worth an estimated $200,000 each, reports the AP. The foundation, which rescues shelter dogs and trains them to become service dogs for the disabled, was founded by The Simpsons co-creator Sam Simon, who died last month at 59, after a long battle with colon cancer.

The paintings were reported missing on April 10, and are thought to have been taken at some point during the previous day. Yesterday, the Los Angeles County police put out a call to the public, seeking information that could lead to the return of the artwork.

An avid art collector, Simon was known to have owned works by Thomas Hart Benton, John Singer Sargent, Ed Ruscha, Dale Chihuly (see Pioneer Glassblower Dale Chihuly Brings New Work and Monumental Favorites to Marlborough Gallery), and photorealist painter Richard Estes. He even had one of Auguste Rodin’s original versions of The Thinker on display in his backyard.

That love of art may have been passed down from his mother, Joan, who owned the Function Art Gallery in Venice Beach, and had many artist friends who would often come visit. “I did know a lot of famous artists growing up,” Simon told Vanity Fair this past October. “Andy Warhol, Claes Oldenburg, Ed Kienholz. Definitely all the California guys, like Chris Burden and Baldessari.”

Over his career, Simon won an impressive nine Emmy awards for his work in television. He left The Simpsons (for an artist’s controversial work based on the hit show, see Police Officer Shoots Black Bart Simpson in Artist’s Take on Iconic Cartoon), which premiered in 1989, after four seasons, but continued to be credited as an executive producer and to receive a share in the profits.

The Sam Simon Foundation was founded in 2002. Following his 2012 cancer diagnosis, Simon announced plans to donate the majority of his fortune, estimated at $100 million, to charity. He also planned to sell his art collection at auction to benefit the foundation following his death.