POLK COUNTY, Fla. (WFLA) — The reward for information in the grisly deaths of three friends out on a nighttime fishing trip last week reached $30,000 Monday.

Polk County Sheriff Grady Judd said the “massacre” has shaken the small city of Frostproof “to its very core.” Frostproof lies roughly 70 miles south of Orlando.

Brandon Rollins, 27, Keven Springfield, 30, and Damion Tillman, 23, appeared to have been beaten and shot to death near a lake in a rural area, according to the Polk County Sheriff’s Office.

“You’ve got three best friends … what is more wholesome than going fishing near Frostproof on a Friday night?” Judd asked during a press conference Monday. “It’s orange groves, cow pastures and a beautiful lake.”

Judd said investigators believe Damion arrived first to the lake in his truck and was murdered by one or more individuals.

The suspect or suspects were in the process of murdering Tillman when investigators believe Rollins and Springfield arrived in another vehicle and were immediately “shot up.”

“Here’s what the murderers didn’t count on,” Judd said. “One of our victims, Brandon Rollins, was able to call his father and say, ‘help.’”

The sheriff said Rollins’ father heard the call, got up, got dressed and drove to the lake. When he arrived, he witnessed what had happened.

Judd said the father was able to have final words with his son, Brandon, before he passed. The information Rollins gave to his father about the suspects remains confidential, the sheriff’s office said.

Judd said their agency has received “well over 100 tips” in the triple homicide case that currently has no suspects.

When asked whether he thinks the murders were a random or targeted attack, Judd said there is “zero evidence” that it was a drug deal gone bad, and it does not appear to be domestic related.

The reward, which started at $5,000 on Saturday, increased to $30,000 Monday after contributions from the Florida Department of Law Enforcement (FDLE) and the Florida Sheriff’s Association.

“We are going to work nonstop until there’s absolutely nothing left to do,” Judd said. “We’ve only had like two unsolved homicides in the last 11 years. My best guess is we solve it. I believe it. But solving it later is not acceptable. We need to solve it now.”