Derrick O'Connell

Derrick O'Connell was a Meteorologist working at S.T.A.R.Labs. He also had a relationship with his co-worker Caitlin Snow before his death.

History
Derrick was a Meteorologist who worked at S.T.A.R. Labs and eventually began a relationship with his colleague, Caitlin Snow. The pair created a "Thermo-Chamber" which was designed to recreate environments to provide better information during experiments.

Death
One day at work Caitlin discovered Derrick cheating on her with another woman. Derrick accidentally turned on the Thermo-Chamber with Caitlin inside and transformed his girlfriend into a metahuman.

Caitlin then came to find Derrick at his house and killed him, covering him in frostbite. His body was then investigated by Barry Allen, who mistakenly believe it to be the result of an "ice-gun".

Trivia

 * Derrick was the first victim of Killer Frost.