According to the criminal complaint, Kostreva had experienced troubles with turkeys eating hay, straw, corn silage and other items during winter at his feed lot the past several years. Up to 500 turkeys per day would appear at the lot, which Kostreva claimed cost him several thousand dollars.
He attempted to solve the problem by contacting personnel at the Wisconsin Department of Natural Resources and other agencies without success. He later obtained information from another source indicating that pouring antifreeze over corn would eliminate the problem, the complaint said.
He then purchased three gallons of antifreeze in January and poured some over corn in a pail, according to the complaint. He then traveled to a nearby pine grove of a neighbor, where turkeys had been gathering during winter, and spread the poisoned corn around trails in that area.
At about 5:30 p.m., Jan. 29, conservation warden Joseph Paul received a telephone call from poaching hotline staff about a confidential call reporting more than 40 dead turkeys. Paul visited the informant, who said a family member had found some of the dead turkeys while snowmobiling. Some other turkeys were still alive but couldn't fly. Many of the dead turkeys had been consumed, as only feathers and bones remained. Most of the birds were in a 2-acre area, the complaint said. Paul and other wardens visited the site and found about 100 dead turkeys.
According to the complaint, DNR veterinarian Julia Langenberg told wardens to transport five turkeys to the animal-health lab for testing. Results were released Feb. 10 that the cause of death was poisoning from ethylene glycol, commonly called antifreeze.
The investigation led to Kostreva. During a Feb. 4 interview, the complaint said, he admitted mixing several pails of cracked corn with antifreeze and spreading it in near the pine grove. He told wardens he did not know that 100 turkeys were found at or near the pine grove. After
putting out the corn, he reported seeing only a few dead turkeys around
Also, the complaint said, Kostreva said he did not know the mixture would have such an effect and that he had not wanted to hurt other animals or people. Further, he said it was out of character for him to do such a thing and offered to help wardens pick up the dead turkeys.