ZION, Ill. (AP) — Cancer Treatment Centers of America is offering a $25,000 reward for information in the death of a Missouri patient beaten to death outside her Illinois hospital residence.

The health care facility announced the reward Thursday. Police are investigating the Monday night beating of 46-year-old Shannon Vincel of Springfield, Missouri, who died Tuesday. Police say Vincel was sitting outside her hospital residence on Monday night when someone hit her in the head with an unknown object. Authorities say she suffered “severe head trauma.”

Authorities have said the attacker was dressed in dark clothing and ran off.

Vincel’s sister, Fabienne Vincel, says she hopes the reward money “leads to the quick capture” of the attacker.

Cancer Treatment Center of America spokeswoman Kirsten Gerlach says security around the Zion facility has been increased.