Updated

A couple tried to hire a hit man to kill their three grandchildren and daughter-in-law to stop them from testifying against their son in his rape trial, authorities said.

The couple, ages 60 and 59, were charged with four counts each of criminal conspiracy to commit murder. They were being held without bond.

Police said they initially offered $100 to an undercover sheriff's deputy to kill their son's wife, their 10-year-old granddaughter, two step-grandchildren, ages 14 and 16, and the family dog. More money was promised after the killings, said Lake County sheriff's Sgt. Christie Mysinger.

The couple's 31-year-old son has been jailed since November on 22 charges of sexual battery on a child, lewd and lascivious molestation and showing obscene material to a minor, court records show.

Detectives say his daughter and stepdaughter are the victims. The Associated Press has withheld the names of the grandparents and the family members to protect the children's identities.

The man tried to solicit a fellow jail inmate to kill his family, the arrest report said. An informant told detectives about the plot and they arranged to meet the man's parents Tuesday at a Best Western motel in Tavares, a lakefront community about 30 miles northwest of Orlando, police said.

"(The deputy) said, 'You want me to kill everyone, including the dog?' They agreed," Mysinger said.

The son's attorney, Peter Sartes, said he had no details on the parents' arrest. It was not clear who was representing his parents.