BRIGHTON — Opening arguments were this morning during the first day of testimony in the first-degree murder trial of William Rex Fowler, the owner of a software company accused of shooting to death his former business partner on Dec. 30, 2009.

Fowler shot Thomas Ciancio to death and then turned the gun on himself because the software company he founded was failing, an Adams County prosecutor said in court today.

Prosecutor Yvette Werner told jurors that Fowler shot Ciancio because Ciancio believed the company owed him money.

Ciancio “paid with his life and his blood,” Werner said.

However, Fowler’s lawyers said Fowler aimed to kill himself, and Ciancio interrupted his suicide attempt.

Both sides in the case claim Fowler Software was failing because Fowler gave as much as $200,000 in company funds to the Church of Scientology.

Fowler, 58, is a prominent member of the Church of Scientology, and the trial has attracted attention from both supporters and detractors of the organization.

However, the allegations that Fowler funneled money from his company to the church are not a factor in the case, Adams County District Judge Francis Wasserman has said. Wasserman barred prosecutors from asking prospective jurors about their views on Scientology.

Fowler allegedly shot Thomas Ciancio three times in the head with a 9mm Glock handgun at Fowler Software after Ciancio came to collect $9,900 in severance pay. Ciancio had resigned his job as chief operating officer of the business in a dispute over the way Fowler was managing the company.

Prosecutors have claimed Fowler shot himself after shooting Ciancio. Investigators at the scene found handwritten notes to Fowler’s wife, Janet, and a briefcase. Janet Fowler later demanded the briefcase be given to her because it contained private information concerning Scientology.

The trial is expected to last through Friday.