Concord District Court Judge Cathy Campbell ordered William Camuti, 69, held without bail until his next court date on Sept. 10 at 2 p.m.
During Tuesday's hearing, which Camuti did not attend, Campbell briefly discussed a question about his competence to stand trial.
Camuti's lawyer, Robert Saltzman, refused to elaborate on the competency and other questions about his client.
Camuti is also facing charges of intimidating a witness and improper disposition of a human body.
Rakes was the victim of poisoning when Camuti allegedly put cyanide in his iced coffee, Middlesex District Attorney Marian Ryan said Friday. Camuti's attempted murder charge is pending full autopsy results to determine the exact cause of death.
According to Ryan, Camuti set a trap for Rakes by meeting him at a McDonald's in Waltham on July 16 to discuss a business deal which did not actually exist.
Camuti allegedly laced the iced coffee with two teaspoons of potassium cyanide, then drove Rakes around for several hours before dumping his body in Lincoln, where it was found on July 17, Ryan said.
Camuti was previously convicted of scamming several Waltham businessmen.