LOS ANGELES, May. 5 — Two defense attorneys in the Hinman-Shea murder case yesterday accused the prosecution of “sensationalism” by not divulging the identity of a key witness.

The charges were made to newsmen by Irving A. Kanarek, representing condemned Tate-LaBianca murderer Charles Manson, and Daye Shinn, who is defending Susan Atkins, also sentenced to die for the killings of actress Sharon Tate and six others.

Manson 36, Miss Atkins 22 and two others are accused in the 1969 slayings of Topanga Canyon musician Gary Hinman and movie stuntman Donald (Shorty) Shea. Hinman was killed shortly before the Tate murders and Shea’s alleged death came afterwards.

Superior Court Judge Raymond Choate scheduled a hearing for May 13 on whether the prosecution must identify the witness.

Dep. Dist. Attys. Burton Katz and Anthony Manzella refused to comment on the charges of sensationalism.

In an affidavit to the court, the prosecutors claimed it is probable that such disclosure would result in the “elimination of that person as a witness or the influencing of his testimony.”

Kanarek told newsmen he wants to know who the witness is in order to prepare his case for trial, which is now scheduled for May 20.

Other pretrial motions, such as change of venue and a defense challenge to the constitutionality of the County Grand Jury and to trial juries, were also scheduled for May 13.