Police: Good Samaritan Florida professor killed by ex-convict he had given $37K to recently

In this arrest photo made available by the Gainesville Police Dept. Friday, March 6, 2015, shows Stephen Underwood Jr, 37. Underwood is under arrest for the murder of retired University of Florida professor, Thomas Oakland. Police at first believed Oakland had died in a fire that consumed his home but an autopsy confirmed that he had been fatally struck in the head and body and was already dead before the fire. Underwood and Oakland had known each other. (AP Photo/Gainesville Police Dept. ) (The Associated Press)

GAINESVILLE, Fla. – Police say a retired University of Florida professor was killed by an ex-convict to whom he'd given $37,000 in recent years.

An autopsy on the professor, 75-year-old Thomas Oakland, found that he'd been fatally struck in the head and body and was likely already dead when fire consumed his Gainesville home on Wednesday.

Police opened a homicide investigation and began searching for a man whom the professor had been helping financially for the past few years.

Late Thursday, they arrested 37-year-old Stephen Underwood Jr. in Jacksonville.

Gainesville Police spokesman Officer Ben Tobias says Underwood knew Oakland kept cash in his home.

Underwood's wife told police her husband recently obtained a large bag of cash. The amount was not immediately clear.