nd times of the events that led to the deaths. There are no cameras or witnesses, he said, and the assaults are believed to have taken place in the early morning hours.

The police department set up camera trailers along the trail, he said, and night shift officers have been assigned to patrol the area.

Asked during a news conference if the department should have warned the public after the death of Dunnebacke in July - he was the second man to die - Backus said it wasn't immediately clear that his injuries were the result of an assault.

Hospital staff initially believed his death could have been from a medical issue, Backus said, though it was investigated by the department's major crimes investigators and treated as a  suspicious situation. 

The manner of Dunnebacke's death has not yet been determined, Backus said.

Samantha Murray contributed.