WEST PALM BEACH, Fla. -- An inmate faces first-degree attempted murder charges after an alleged plot to kill his wife failed for a second time.

Police said Christopher Hoar, who remains behind bars after confessing to hiring a hit man to kill his wife 10 months ago, recently did the same thing again -- this time, plotting behind bars with another inmate to murder his wife, Marcia Hoar.

Authorities said Marcia Hoar worked with detectives by posing as dead, complete with fake blood, for a digital image that was shown to Christopher Hoar after he allegedly hired a Colombian hit man to kill her.

"He's a very determined man," said Jenell Atlas of the Martin County Sheriff's Office. "He wants his wife killed."

Detectives said Hoar made an agreement with the hit man to pay him $15,000 to kill Marcia Hoar. Because he's in jail, he could only give a down payment of $1,000. They said Hoar wrote a bill of sale to transfer ownership of his car to the would-be killer for the down payment.

Detectives said the most troubling part of the case is Christopher Hoar's persistence.

"We're concerned about this, because one of these days, he's going to get the right inmate to kill his wife," Atlas said.

Sheriff's officials said they are mindful of the security concerns for Marcia Hoar, and they will take precautions to make sure she is safe.

Hoar did not confess to the most recent alleged plot as he did the last one.