CONCORD, N.H. (AP) A teen-ager accused of killing two Dartmouth College professors will use an insanity defense at his trial, his lawyer said in a court filing Friday.
Robert Tulloch, 18, of Chelsea, Vt., will argue he suffers from a ''severe mental defect or disease and that his acts were the direct result of the mental defect or disease,'' public defender Richard Guerriero said in the filing.
Tulloch's trial is set for April 8 in Grafton County Superior Court.
Tulloch and his friend, James Parker, 17, are charged with first-degree murder in the Jan. 27. stabbing deaths of Half and Susanne Zantop in their Hanover home.
No motive for the crime or connection between the Zantops and the suspects has ever been given publicly. A law enforcement source has told The Associated Press the Zantops were probably killed during a burglary gone awry.
A trial date for Parker has not been set, as prosecutors seek to have him certified to stand trial as an adult. He was 16 at the time of the murders.
Prosecutor Kelly Ayotte said she was first informed of the insanity issue late Thursday.
''I've read the notice of defense in its entirety and the state is fully prepared to meet this at trial,'' Ayotte said.
She declined to comment further.
Doug Brown, one of Parker's lawyers, told the AP his client will not use an insanity defense. Brown said based on Tulloch's decision, Parker's lawyers have re-evaluated their strategy.
''We will be making a major announcement regarding our case on Monday,'' Brown said from his San Diego office.
A source close to the case said there may be a plea from Parker, but wouldn't be more specific.
Guerriero said the defense had a psychiatrist evaluate Tulloch.
The filing says that while lawyers did not notify the court of the planned defense within the initial deadline for such notices, the case is so complicated that extra time was needed to evaluate Tulloch.
It was difficult at first to recognize the illness due to ''Robert's intelligence and his particular personality,'' the filing says.
Court rules require notice of an insanity defense be given within 10 days of a defendant's plea in Superior Court, but the deadline can be extended if good cause is shown.
Judge Peter Smith will review the defense request next week, said Grafton County Superior Court Clerk Bob Muh.
The filing notes that prosecutors have not taken a position on the request to extend the deadline for notice of an insanity defense.
Prosecutors say they found fingerprints and footprints in the Zantops' home that link the teens to the murders. Court documents say two military-style knives stained with the victims' blood were found hidden in Tulloch's bedroom.
The two teens were arrested at an Indiana truck stop on Feb. 19.
Parker, meanwhile, was initially charged as an adult while on the run, but his case reverted to juvenile status once he was returned to New Hampshire.
Several closed-door hearings, the details of which have not been released, have been held over the last year to determine if Parker will be tried as an adult.
Most states specify a minimum age for which violent offenders can be tried as adults under certain circumstances. In New Hampshire, it's age 13.
New Hampshire law automatically considers 17-year-olds adults in criminal cases.
Courts must consider eight criteria when determining if a juvenile should be tried as an adult, including the seriousness of the crime, the sophistication and maturity of the suspect, the defendant's prior contact with law enforcement and the prospect that the person could be rehabilitated.
Eric Wilson, a Nashua lawyer who specializes in juvenile issues, said it is rare for a New Hampshire court not to certify a juvenile as an adult when petitioned to do so in a murder case.
As many as 20 juveniles facing some kind of homicide charge have been ordered to stand trial as adults in the last decade or so.
One of the more recent was 14-year-old Jeffrey Dingman, who eventually pleaded guilty to helping his 17-year-old brother kill their parents in Rochester in 1996.
Half Zantop, 62, taught earth sciences at Dartmouth, and his wife, Susanne Zantop, 55, was chairwoman of the German studies department.
