A former Russian spy and his daughter who were poisoned in a nerve gas attack in England could have lasting brain damage, British officials said.

Sergei Skripal, 66, and his daughter Yulia, 33, were found slumped on a bench in Salisbury, England, on March 4.

A police officer who was exposed to the toxin was released from the hospital Thursday.

“There are really no words to explain how I feel right now,” said Detective Nick Bailey, 33.