Delphi has raised $176,000 to add security on its 10-plus miles of trails.
State Police Sgt. Kim Riley says officers are working their way through the tips generated by the July 17 release of an FBI artist's sketch of the man.
Indiana State Police are seeking the public's help in identifying a person suspected of murdering two teen girls in Delphi in February.
The campaign aims to raise $50,000 by Aug. 30 for improvements.
Authorities say around 13 people have been arrested based on pending warrants against them unrelated to the slayings.
A 5-kilometer run on June 10 will serve as fundraiser for the trail changes.
Donations have boosted to the reward to $96,000 for information in the killings of 14-year-old Liberty German and 13-year-old Abigail Williams in Delphi.
Investigators have moved to a larger headquarters as they work on finding who killed two teenage girls.
Police say one of the two teenage girls killed last week in northern Indiana recorded the voice of a suspect in their deaths.
The man previously had been considered a person authorities wanted to speak to in the investigation.