Slain Man Called Victim of Forgery : Crime: Prosecutors say millionaire’s fiancee stole $500,000 by signing his name to checks, the last dated the day he was shot.

Prosecutors alleged Tuesday that the fiancee of slain millionaire William Francis McLaughlin stole $500,000 by forging his checks, the last of which was dated the day he was shot to death at his Balboa Coves home.

If convicted of 15 counts of forgery and one count of grand theft, Nanette Johnston, 29, of Newport Beach would face a maximum sentence of 10 years, Deputy Dist. Atty. Joe D’Agostino said.

She is charged with forging checks dated from Jan. 10, 1994, to Dec. 15, 1994, including one for $250,000, D’Agostino said. A handwriting analysis concluded that the signatures were not McLaughlin’s, he said.

Beyond saying, “We still don’t have enough to charge her for homicide,” Newport Beach Police Sgt. Andy Gonis declined to comment on whether the charges will be linked to investigation of the McLaughlin slaying.

Johnston and her boyfriend, former New England Patriots linebacker Eric Naposki, are suspects in the December slaying of the 55-year-old McLaughlin, police said. McLaughlin’s body was found by his son, Kevin, with six gunshot wounds to the chest, prosecutors said.

Attorneys for Johnston and Naposki said they both have alibis. Johnston told police that she had been shopping in Costa Mesa at the time of her fiance’s death, and Naposki said he had been on his way to work and made a telephone call just minutes before the shooting.

According to a search warrant affidavit earlier this year, Johnston stood to inherit at least $150,000 from McLaughlin’s estate, amassed partly through medical product developments that included a device to separate plasma from donated blood.

Naposki became a suspect after police found suspicious items in his vehicle, including several brown and red stains on the carpet and a green towel with what appeared to be dried bloodstains.

Naposki’s lawyer, Julian Bailey, said the former linebacker has submitted blood samples to police for analysis, but results were not available from police Tuesday.

Johnston was being held at the Orange County Jail in lieu of $500,000 bail. But under a court order, she may not post bail unless she first proves the money was not stolen money, D’Agostino said. The bail hearing was scheduled for today. Naposki’s attorney, Julian Bailey, said he believes that Johnston and McLaughlin had been business associates and that Johnston had permission to sign his name to business checks.

But D’Agostino said statements from witnesses indicated that Johnston and McLaughlin had a personal and not a business relationship.

Johnston’s attorney, Barry Bernstein, would not comment on the case.