Police have arrested a 59-year-old Lincoln man, saying they suspect him of bugging his 90-year-old mother’s phone.

Richard Stamler was arrested Thursday night on suspicion of unlawful interception of communications.

Police spokeswoman, Officer Katie Flood, says the man’s sister called police on March 28 to report that she had found a recording device connected to her mother’s phone line and recognized her brother’s voice recorded on the device.

Police say a letter written by the man to his sister demands documentation of his mother’s savings and threatens the sister with legal repercussions if she stands between him and his mother.