A father was convicted on Saturday of injecting his 11-month-old son with blood tainted with H.I.V., the virus that causes AIDS, in order to avoid paying child support.
Jurors returned their verdict after deliberating for about eight hours. They recommended life in prison for the man, Brian Stewart, 32, of Columbia, Ill. Sentencing was scheduled for Jan. 8.
The boy's mother, identified only as Jennifer to protect the boy's identity, wept briefly after the verdict was read.
Prosecutors used circumstantial evidence to convince the jury that Mr. Stewart, who once worked as a hospital technician, stole H.I.V.-infected blood from his workplace and injected it into the boy in 1992, during a hospital visit. The boy was being treated for asthma and pneumonia.
The victim, now 7, developed AIDS. Prosecutor Ross Buehler called the injection a death sentence for the child.
"He had the knowledge and training to commit this offense," Mr. Buehler said of Mr. Stewart during closing arguments. "And more importantly, had the motive."
Prosecutors claimed that Mr. Stewart tried to kill his son to avoid child support payments.
Defense attorney Joe Murphy denied the allegations, saying the prosecution presented no actual proof that Stewart injected his son.
"A tragedy is not a crime and theories are not facts," Mr. Murphy said. "Mom made an allegation and everyone ran with it."
Mr. Stewart is expected to appeal.
Jennifer met Mr. Stewart in January 1990, and became pregnant five months later. She testified that she gave birth to their son in February 1991 and that her relationship with Mr. Stewart ended in August 1992.
The boy stays alive with the help of a round-the-clock regimen of tube feedings and medications.