Prosecutors say the reward for information leading to the arrest and conviction of whoever left poisoned meatballs at a Gunbarrel park -- sickening three dogs -- is now up to $3,500.

Catherine Olguin, a spokeswoman for the Boulder County District Attorney's Office, told The Daily Camera on Friday afternoon that one resident had donated $1,000 for information in the case, and more donations have poured in since.

Authorities have recovered eight meatballs laced with rat poison from the park at 5150 Buckingham Road since Monday, and veterinarians are monitoring the three dogs.

Animal control specialist Sara Spensieri says she may know more once the Colorado Bureau of Investigation releases the results of a human DNA test it's conducting on two of the meatballs.