Investigators are working to determine the details of a dispute over a family trust worth millions that they believe led an Indiana man to kill his niece, her 4-year-old son and then himself.

Lucius Oliver Hamilton III, who worked as a college fundraiser, fatally shot himself inside a hotel room one block from the Indiana Statehouse just after officers knocked on the door, state police Capt. Dave Bursten said. Hamilton, 61, had been the subject of a manhunt since shortly after the bodies of Katherine Giehll and Raymond Peter Giehll IV were found Wednesday morning in their home in an upscale neighborhood near Zionsville, just northwest of Indianapolis.

Boone County Sheriff Mike Nielsen said a neighbor found Katherine Giehll, 31, dead around 8 a.m. just inside the home and her son was in the living room, where he had been watching television. Nielsen said investigators believed the dispute over the family trust led to the attack.

"I think there are millions of dollars involved here," he said. "It is a lingering issue that has been going on for the last few years."

Hamilton was the senior major gifts officer for Wabash College, a private, all-male liberal arts school in nearby Crawfordsville, according to the college's website. The campus there was placed on lockdown while police officers searched buildings. Classes were canceled for the rest of the day.

Bursten said Hamilton acknowledged officers after they knocked on the door of a fourth-floor room in a Hilton hotel and that two shots were fired from inside about 3 p.m. Wednesday.

No other injuries were reported, and Bursten said only one other hotel guest was on the floor when officers arrived.

Bursten said Hamilton was the brother of the Katherine Giehll's father.

"I think what tears into anybody in the community or any police officer is when you have such a young innocent life and the mother, it goes beyond comprehension and words what goes into somebody's mind to make them do something like that," he said.

Wabash College President Gregory Hess said the school was cooperating fully with investigators and counseling services were being provided for students and employees.

"All of us at Wabash College are deeply saddened by the events that unfolded in Zionsville this morning, and we extend our condolences to all who are affected by these tragedies," he said in a statement.