Federal prosecutors say the 78-year-old father of a convicted Connecticut killer who was captured in Mexico after two decades on the run should go to prison for six months for helping his son flee the country and sending him money.

Prosecutors wrote in court papers Monday that Frederick Zachs of West Hartford concocted a plan to help his 48-year-old son, Adam Zachs, "literally get away with murder." Authorities say the plan worked for two decades, "exacting a terrible toll" on the victim's family and friends.

Frederick Zachs is asking to be spared prison time, citing his fragile health and other factors. He pleaded guilty in June to harboring a fugitive and is scheduled to be sentenced Friday.

Adam Zachs, who was convicted in 1988 of fatally shooting a man outside a restaurant, was captured in February.