(CNN) -- Ohio Gov. Ted Strickland on Tuesday gave a death-row inmate a one-week reprieve after authorities tried for hours to find a vein to administer his lethal injection.

Romell Broom was convicted of raping and killing a 14-year-old girl in Cleveland, Ohio.

"Difficulties in administering the execution protocol necessitate a temporary reprieve," said Strickland's Warrant of Reprieve, filed in court Tuesday afternoon in the case of inmate Romell Broom.

Broom's defense attorney, Tim Sweeney, wrote Ohio Supreme Court Chief Justice Thomas Moyer on Tuesday that, "I am advised by my co-counsel, Adele Shank, who is at the prison in Lucasville, that the execution team has been attempting since approximately 1 p.m. this afternoon to obtain IV access to a site in Mr. Broom's body in order for the lethal injections to be administered, but without any success.

"It appears ... that these efforts have been going on now for almost two hours, and that the execution team members have evidently now taken a 'break,' " Sweeney wrote.

Broom's execution was initially scheduled for 10 a.m. ET, but was delayed for legal reasons and rescheduled for Tuesday afternoon, Sweeney told CNN.

"When such allegedly skilled professionals have taken this much time without successfully achieving IV access, there comes a point of diminishing returns, and a point when further attempts are cruel and counterproductive," Sweeney wrote to Moyer. "I believe we have reached that point here."

Sweeney had earlier said he was in the process of filing an appeal to halt the execution for Tuesday, claiming it was not being carried out according to the state constitution.

Calls by CNN to state officials were not immediately returned.

Strickland's document directs the Ohio Department of Rehabilitation and Correction to carry out Broom's execution on September 22, "unless further reprieve or clemency is granted."

Broom, 52, was convicted of murdering a 14-year-old girl in Cleveland in 1984, according to a death clemency report.

In May 2006, Ohio officials took nearly 90 minutes to carry out the execution of Joseph Clark because of problems finding a vein. Once they did find one, it collapsed, according to the Toledo Blade. Clark repeatedly shook his head, according to the newspaper, and told officials, "It don't work."

A year later, Ohio inmate Christopher Newton's execution reportedly took two hours after a prison team had trouble finding a vein.

CNN's Chuck Johnston contributed to this report

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