POLK COUNTY, Fla. - Polk County officials say they've received more than 100 tips in connection to the murders of three best friends who were on a fishing trip.

What You Need To Know

The victims were identified as Brandon Rollins, 27, Kevin Springfield, 30, and Damon Tillman, 23.

They were on Lake Streety fishing Friday night near U.S. Highway 27 prior to being killed, according to Sheriff Grady Judd.

On Monday, the Polk County Sheriff's Office said it's increasing the reward to $30,000 for any information that leads to the arrest of the suspects.

That is up from the original reward offer of $5,000.

Judd said his agency believed the suspect or suspects were killing Tillman when Rollins and Springfield showed up and were shot. Judd said Rollins was able to call his father and ask for help before that happened.

It’s unlikely to be a random act of violence, considering the isolated nature of the lake, according to the sheriff's office.