Brady Harmon said he was days away from reuniting with his four children when police found them dead with their mother and grandmother in a Mechanicville apartment.
Police identified the children as Harper, 13, Hudson, 11, and 10-year-old twins Gavin and Gracelyn, and said evidence points to intentional poisoning.
Harmon, speaking from Salt Lake City, said he had spent 6 years seeking custody or visitation and planned to pick the children up July 1 for the summer.
The father said he had not seen the children in person since November 2019, while investigators continue probing the six deaths and the grandmother has been eyed as a suspect.