DENVER -- Denver police are looking for attacker after the founder of Colorado Free University was stabbed to death over the weekend.

John Hand, 55, was stabbed inside his Hilltop apartment on the 700 block of Elm Street around 1 a.m. Sunday.

The landlord called police after hearing a struggle in one of the adjacent apartments. The landlord started to climb upstairs to help when he heard Hand shouting that someone was trying to kill him. The landlord then rushed to call 911.

When police arrived, they found Hand alone on the floor suffering from a stab wound. Hand was transported to Denver Health Medical Center where he was later pronounced dead.

Investigators do not have any one in custody or a possible motive. The landlord did not see anyone leave or enter the complex, police said.

Friends describe Hand as a gentle yet passionate person who wanted to challenge people to grow personally and empower communities to connect. His community-based school for adults opened in 1987 and offers low-cost classes in a variety of topics ranging from investing, gardening to cooking and clubbing.

The school posted this statement on its Web site FreeU.com: "In light of the recent events, the Colorado Free University staff would like to thank the community for its condolences and support at this tragic time. Our offices will remain open and classes will run as scheduled. We are doing our best to keep the Free University running as we feel John Hand would have wanted. We will post any further information as it becomes available, including service arrangements."