The death of a 99-year-old man following a home invasion last month in Crystal has been ruled a homicide.

John Mathias Gosche suffered blunt-force injuries to his left arm during an altercation with robbery suspects who entered his home in the 4100 block of Colorado Avenue N. on the afternoon of Dec. 2 and demanded money.

Gosche died four days later at North Memorial Health Hospital in Robbinsdale of sepsis complications from his injuries, the Hennepin County Medical Examiner's Office said in ruling his death a homicide.

The medical examiner released the cause of death on Thursday, the same day Crystal police said detectives are continuing to investigate.

According to police, two male suspects "physically forced" Gosche around the house as they demanded money. They left with an undisclosed amount of cash. No weapons were believed to have been shown during the robbery, which occurred about 2:20 p.m.

Gosche was taken to a hospital and treated for his injuries. He was released, but a few days later suffered medical complications from his initial injuries that led to his death.

Gosche, who earned a degree from the University of Minnesota, was a longtime dentist at Inka Dental on 42nd Avenue N.

Police have not made any arrests, nor have they released any information about the suspects. They do not believe the incident was random and say there is no danger to the public, Deputy Police Chief Brian Hubbard said.

"We are working as diligently as we can" to solve this case, Hubbard said. "This is tragic."

Gosche's wife, Geraldine, 91, was home at the time of the robbery, but was not hurt. She died about a week after the robbery of natural causes, Hubbard said.

Anybody with information is asked to call the Crystal Police Department's tip line at 763-531-1020.

Tim Harlow • 612-673-7768