Jonathan McKinney pleaded not guilty to charges of Class AA felony murder and two Class C felony counts of tampering with evidence.
Warren Pfetzer pleaded not guilty to two Class C felony charges of tampering with evidence, along with additional Class C felony charges of terrorizing and felon in possession of a firearm.
A jury trial in the case is set to start Oct. 28, and the court has set aside eight days for the trial. A pretrial conference will be Sept. 29.
McKinney is accused of shooting Lansdon, 28, several times with a .42 caliber rifle. Lansdon was found dead at his mobile home in southeast Mandan around 10 p.m. Jan 27.
McKinney and Pfetzer then are accused of taking shell casings from Lansdon's residence, moving the body and shooting his body after he had died. They also allegedly arranged to have the rifle destroyed.
The two men lived together a few houses away from Lansdon.
Pfetzer is also accused of threatening a confidential source with a firearm, which counts for his additional two felony charges.