A man in Maryland was arrested and charged with threatening to kidnap and kill Biden and Harris.

A man in Maryland has been arrested on charges that he threatened to kidnap and kill Joseph R. Biden Jr., the Democratic presidential nominee, and his running mate, Senator Kamala Harris, law enforcement officials said on Wednesday.

A criminal complaint filed by the Secret Service on Wednesday did not describe any steps taken by the man, identified as James Dale Reed, to carry out the alleged threat. It said that on Oct. 4, Mr. Reed approached a house in his hometown, Frederick, Md., northwest of Washington, that had Biden-Harris campaign signs in the yard and left a handwritten note that contained graphic threats against the candidates and their supporters.

The resident’s video doorbell had captured an image of the man who left the note, the complaint said.

“We are the ones with these scary guns, we are the ones your children have nightmares about,” the note read in part. Mr. Reed, 42, was arrested last Friday and is being held without bond in Frederick County, Md., according to court records. A spokeswoman for the Maryland Office of the Public Defender, which is representing Mr. Reed, declined to comment.