Connecticut Superior Court Judge Harold M. Mulvey yesterday declared a mistrial in the six-month proceedings against Black Panther leader Bobby Seale ending a 23-hour jury deadlock.

State Attorney Arnold Markle said yesterday that he will try to get a retrial for co-defendants Seale and Ericka Huggins, both charged with the kidnapping and slaying of Alex Rackley, another Panther member.

Judge Mulvey made his decision after the jury, composed of five blacks and seven whites and selected over a four-month period, insisted they could not agree on a verdict.

Judge Mulvey will meet today with the two defendants, their attorneys and the prosecuting attorney, and is expected to decide whether the defendants will be released on bail and to set a date for a retrial.

Black Panther attorney Theodore Keskoff said he will ask that all charges be dropped on the grounds that the state already found it could not sustain a "reasonable doubt" in the case. "How many shots should the state get?" Keskoff said yesterday.

State prosecutor Markle said yesterday, "I absolutely will prosecute the case again."

When Seale and Huggins left the court building after the verdict, about 100 supporters met them with chants of "Free Bobby and Ericka," and Seale returned a handcuffed fist.