TOPEKA, KAN. – A man from Manhattan, Kan., has pleaded guilty to taking part in an armed robbery that set in motion a series of events leading ultimately to a deadly arson in which a Kansas State University researcher died, U.S. Attorney Barry Grissom said today.

Dennis James Denzien, 20, Manhattan, Kan., pleaded guilty to one count of aiding and abetting a robbery. In his plea, Denzien admitted that on Feb. 6, 2013, he drove co-defendant Frank Joseph Hanson to Dara’s Fast Lane at 1816 Claflin Road in Manhattan. Wearing a mask and brandishing a revolver, Hanson entered the store. After Hanson robbed the store, Denzien drove him away from the scene of the robbery.

Later that day, Riley County Police Department officers served two search warrants at a residence where Denzien lived with another defendant, Patrick Martin Scahill. Ultimately, investigators recovered a mask, gloves, a backpack and a firearm used in the robbery.While officers were working to obtain one of the warrants they served at Denzien’s residence, Hanson, Scahill, defendant Virginia Amanda Griese, defendant Gavin Hairgrove and another person met and discussed what would happen if the police searched the residence and how to distract police long enough for Scahill to re-enter the residence and remove incriminating evidence.

In the end, Griese drove Scahill to the Lee Crest Apartments at 820 Sunset Avenue in Manhattan. Scahill poured gasoline in a hallway of the building and set a fire, hoping to distract police from searching the residence, which was across the street from the apartments. Vasanta Pallem, a post graduate researcher at Kansas State University who lived on the third floor of the apartments, was overcome by smoke and unable to escape the burning building.

Denzien is set for sentencing Aug. 5. He faces a maximum penalty of 20 years in federal prison and a fine up to $250,000 on the robbery count; and not less than seven years consecutive to the underlying penalty on the firearm charge.

Other defendants include:

Frank Joseph Hanson, who pleaded guilty to robbery and is set for sentencing July 8.

Patrick Martin Scahill, who pleaded guilty to arson resulting in a death and is awaiting sentencing.

Virginia Amanda Griese, who pleaded guilty to arson resulting in death and is set for sentencing July 8.

Gavin Taylor Hairgrove, who is set for a change of plea hearing June 10.

Grissom commended all the investigators and law enforcement agencies that worked on the case, including the Bureau of Alcohol, Tobacco, Firearms and Explosives, the Riley County Attorney’s Office, the Riley County Police Department, the Manhattan Fire Department, the Kansas State Fire Marshal’s Office, the Kansas Bureau of Investigations and the Pottawatomie County Sheriff’s Office, as well as Assistant U.S. Attorney Jared Maag, Special Assistant U.S. Attorney Barry Wilkerson and Special Assistant U.S. Attorney Barry Disney, who are prosecuting.