A sexual assault at Ijams Nature Center, and a groping at UT Gardens.
The latest bizarre story happened, at the Jean Teague Greenway in West Hills.
Police do have a person of interest but so far, no charges.
A woman says a man came up behind her and threatened her with a knife, but he took off.
Now police are beefing up patrols and Knox County Parks and Rec. have had a plan in the works for months, they hope helps.
So, is it safe to use Knox County's greenways?
Sgt. Shawna Williams, with the Knoxville Police Department says it is.
"We have been able to boost up park patrol and we have officers in our parks from daylight to dusk, and we actually schedule and one hour after dark."
But it's not just cops. Knox County Parks and Rec. has a plan of its own.
Doug Bataille, Senior Director of Knox County Parks and Rec says they're bringing in about 60 people to rain, "they'll have special shirts on that will be identified. All of them, they will be bike riders, they will be walkers, they will be runners."
And along with those patrols, protect yourself.
"Obviously you need to make sure you're keeping your head up and paying attention to your surroundings," says Williams.
Bataille says this initiative has been in the works for months, he says it's necessary with more people on the trails.