Argued Dec. 14, 1989.
Brian M. O'Connell, Hartford, for appellant (defendant).
Rita M. Shair, Deputy Asst. State's Atty., with whom were James E. Thomas, Asst. State's Atty., and, on the brief, John M. Bailey, State's Atty., for appellee (state).
Before PETERS, C.J., and ARTHUR H. HEALEY, CALLAHAN, GLASS and HULL, JJ.
[214 Conn. 123] CALLAHAN, Associate Justice.
The defendant, Michael Walker, was charged in a substitute information with murder in violation of General Statutes §§ 53a-54a(a) and 53a-8, conspiracy to commit murder in violation of General Statutes §§ 53a-54a(a) and 53a-48(a) and assault in the first degree in violation of
General Statutes §§ 53a-59(a)(1)  and 53a-8. After a jury trial, he was found guilty of all the charges and was subsequently sentenced by the trial court to an effective term of imprisonment of eighty years.
The defendant claims on appeal that the trial court erred in: (1) denying his motion for a new trial because of the state's delay in disclosing exculpatory evidence; [214 Conn. 124] and (2) allowing into evidence the testimony of a witness for the state that she had been threatened. We find no error.
The record discloses that the defendant and Tracey Fisher  were arrested in connection with the death of Thomas Dixon and the wounding of Barrington Solomon. The shooting occurred on the evening of May 12, 1987. Dixon and Solomon were seated, conversing on the first floor rear porch of a multiple family dwelling located at 104 Enfield Street in Hartford. The defendant and Fisher approached the dwelling and fired bursts from a .30 caliber automatic or semi-automatic weapon at the men on the porch. The shots killed Dixon instantly and severely wounded Solomon. The shooting was apparently motivated by the defendant's desire to avenge his brother, Robert Walker, who, on a previous occasion, had been shot by Solomon and, as a result, was paralyzed. 
At the defendant's trial the state offered Lehman Brown  as a witness. Brown testified that he knew the defendant and Fisher and that he had been with them early in the day on May 12, 1987. Thereafter, he said, he had gone to visit a friend, Dion Smith, at her apartment. Brown testified that Smith resided at 98-100 Enfield Street, the premises adjoining 104 Enfield Street where Dixon and Solomon were shot. Brown stated that he had fallen asleep at 98-100 Enfield Street and that upon awakening in the evening he had gone out on a rear porch. While there, he observed the defendant and Fisher come through the back lot behind [214 Conn. 125] 98-100 Enfield Street. Fisher was in possession of an automatic weapon. Brown stated that he then saw Fisher scale a fence between the properties and fire a series of shots at the men on the porch. Fisher then returned to where the defendant was standing and handed him the gun. The defendant then fired a burst from the weapon at the porch. Fisher and the defendant then ran from the scene.
Smith, Brown's friend, did not testify in the state's case-in-chief nor did she testify
for the defense. After the defendant had rested his case, however, the state called her as a witness on rebuttal. Smith testified that she had known Brown for approximately two and one-half years. She stated that, although she had been with Brown on May 12, 1987, she had never been with him in or near an apartment at 98-100 Enfield Street in Hartford. Smith was not cross-examined by the defendant.
During the state's closing argument to the jury the prosecuting attorney noted that he had called Smith as a witness because he had a duty to see that the defendant received a fair trial and that he was obligated to produce all the relevant evidence whether it helped or hurt the state's case. He then stated that Smith's testimony indicated that the state's witness, Brown, "was probably not on the porch at 100 Enfield Street on the night in question." 
The defendant claims that the trial court erred in denying his motion for a new trial because of the state's failure to promptly disclose Smith's exculpatory testimony prior to calling her as a witness. He argues that the lack of prior disclosure amounted to the suppression[214 Conn. 126] of exculpatory evidence and deprived ...