A medical marijuana dispensary owner who authorities called the “mastermind” behind a conspiracy to harm a rival dispensary owner and former landlord pleaded guilty on March 28 to multiple felony counts.

The defendant, Andrew Harrison Kramer, 39, accepted a plea agreement with prosecutors, and is scheduled to return to court on Wednesday, April 9, for sentencing. He is expected to be sentenced to 25 years in state prison, per the plea agreement, Los Angeles County District Attorney’s Office spokeswoman Jane Robison said.

Kramer was charged with multiple felony counts of conspiracy to commit a home invasion robbery, stalking, attempt to burn, arson and arson of an inhabited structure. The defendant formerly operated three dispensaries in West Hollywood and Marina Del Rey, including the now-defunct Sunset Super Shop dispensary in the 8900 block of Sunset Blvd.

The charges stemmed from a dispute Kramer had with George and Nancee Lanning, who owned the building where the Sunset Super Shop was located. The dispute reportedly originated when the Lannings evicted Kramer in 2009.

The Lannings continued to operate the dispensary themselves for a year after evicting Kramer, but closed the shop in 2010 after the city of West Hollywood determined it was operating illegally under city ordinances. Authorities determined Kramer conspired with four accomplices to assist in the plot against the Lannings.

The incidents began on Aug. 9, 2010, when Kramer and two of his accomplices allegedly threw a firebomb at the building on Sunset Boulevard. A second arson occurred at a nearby building also owned by the Lannings on Sept. 24, 2010, allegedly involving Kramer and one of his accomplices. The fires damaged the structures but no injuries were reported. An additional arson fire occurred on Jan. 11, 2011, at a property owned by the Lannings at 370 N. San Vicente Blvd.

On Feb. 5, 2011, Kramer also allegedly set fire to a residence owned by the Lannings on Le Deux Road in Beverly Hills. Kramer and an accomplice also allegedly confronted the Lannings and their son at an undisclosed location on Jan. 30, 2012, and struck them with a crowbar. Kramer was arrested on April 16, 2013, along with the alleged accomplices, who were identified as Ronald Samuel, 41; Rene Johnson, 51; Jonathan Livingston, 44; and Grace Cox, 50, all of Los Angeles. Robison said the additional suspects have also already been convicted. Cox was sentenced to nine years in state prison, Johnson was sentenced to seven years in prison, and Livingston received a six-year prison sentence. Samuel is expected to return to court on July 22 for sentencing The different lengths of the sentences resulted from the severity of the roles they played in committing the crimes, Dep. District Attorney Renee Rose said.

The case was investigated by the Beverly Hills Police Department, in conjunction with the Los Angeles Police Department, the Los Angeles County Sheriff’s Department and the federal Drug Enforcement Agency.