(CNN) -- It's perhaps the unanswered questions after Brandon Goode's death that will haunt his parents the most. "Words do not exist to express the measure of our sorrow and sadness," Ricke and Connie Goode said in a statement issued Wednesday to CNN affiliates WESH and Central Florida News 13. "Whether mental illness, substance abuse or something else, we are a family searching." Brandon Goode, 18, and Alexandria "Alex" Hollinghurst, 17, both of Davenport, Florida, are accused of fatally shooting a police officer before apparently committing suicide. Windermere police Officer Robert German called for support after witnessing Goode and Hollinghurst -- who had been reported missing -- walking along a street early Saturday. But when backup arrived, German was found lying on the ground, suffering from a gunshot wound, according to Polk County authorities.
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Police responded to a report of an officer shot and heard more gunshots during rescue
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Nearby, authorities found the bodies of Brandon Goode, 18, and Alexandria Hollinghurst, 17
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Goode and Hollinghurst had both left suicide letters; one of Hollinghurst's was scathing
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Chief: Robert German was "one of the finest police officers that we had in this agency"
"To my loving parents, I am sorry for all the pain and misery I have brought you both, not just now but from these past few years as well," begins @placeholder's note, hand-written in neat, even letters.