LOS ANGELES—A Los Angeles actor who appeared in low-budget horror and science-fiction movies is expected to plead guilty today to running a $650 million Ponzi scheme. Zachary Joseph Horwitz, who used the name Zach Avery in film credits, allegedly bilked investors who thought their money would finance distribution rights for movies that would run on HBO and Netflix, according to the U.S. Attorney’s Office. Horwitz, who lives in the Beverlywood area, has agreed to plead guilty to one federal count of securities fraud, which carries a sentence of up to 20 years behind bars, court papers show. The U.S. Securities and Exchange Commission also sued Horwitz and his firm, 1inMM Capital LLC, in civil court over the alleged scam, which involved the sales of film-licensing rights, primarily in Latin American markets. Horwitz, 34, operated 1inMM Capital as a Ponzi scheme, using victims’ money to repay earlier investors and to fund …