An autopsy is scheduled this morning on the body of an 33-year-old Nicholas Mathew.
Mathew's body was discovered in his apartment on Evansville's east side on Christmas Eve.
Police say he suffered multiple stab wounds.
A possible suspect in Mathew's death, 24-year-old John Jackson, Jr., is already in jail. He's accused of stabbing and robbing an Evansville cab driver.
So far, Jackson has not been charged in Mathew's death.
The victim's sister says she doesn't know of any connection between Jackson and her brother.
Megan Mathew says her brother was happy and ready for Christmas.
Megan says she last saw Nicholas at a birthday party for her son on Sunday.
Two days later, on Christmas Eve, Megan's mother called 911 after Nicholas didn't answer the door to his apartment on Hatfield Drive.
Police say John Jackson, Jr. admitted to being in Mathews apartment and robbing him, but denies any knowledge of his death.
Meanwhile, Megan says she and her family are preparing for the long road ahead, "To be killed like this, I just don't know if I will ever understand it. And I just want everybody that was involved to be brought to justice."
A memorial service for Nicholas Mathew is scheduled for Monday at 4:00 p.m. at East Side Christian Church.
Donations can be made in Mathews' name to the AIDS Resource Group or Matthew 25.