MADISON, Wis. -- Madison police have released more information on Sunday about the slayings of resident Joel Marino and University of Wisconsin-Madison student Brittany Zimmermann.

Authorities said Marino and Zimmermann's deaths don't appear to be connected. However, in a statement released on Sunday, police said they can't totally rule out any connection, mainly because of certain similarities.

Those similarities include that the victims were killed inside their homes, were in close proximity to each other and there was nothing in either case to suggest the victims had enemies or were at risk due to their lifestyles.

Marino, 31, was fatally stabbed inside his home off South Park Street in January. Police have released a sketch of a possible suspect but still don't have a name.

About one mile away, Zimmermann, 21, was slain inside her apartment in April. An autopsy determined she died of a complexity of traumatic injuries.

Authorities have questioned several people but don't have a suspect.

Madison Police Chief Noble Wray and Assistant Chief Randy Gaber have offered to meet with Marino's father Lou Marino on Tuesday. Police said that they want to talk about the case and Lou Marino's recent comments about the investigation.

Lou Marino has not said whether he will meet with police.