By Daily Mail Reporter PUBLISHED: 15:10 EST, 22 January 2014 | UPDATED: 18:44 EST, 22 January 2014 No clemency: Edgar Tamayo will be executed for murdering Houston police officer Guy Gaddis in 1994 A Mexican held on death-row in a Texan prison for murdering a policeman will be executed tonight despite last-ditch appeals from lawyers for clemency. Edgar Arias Tamayo, 46, was set for lethal injection this evening for shooting of Guy Gaddis, 24, in January 1994. The case has been a focus of protests in his home town and diplomatic pressure, with U.S. Secretary of State John Kerry calling for a delay to Tamayo's execution.
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Edgar Tamayo is scheduled for lethal injection at a Texas prison
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Death-row inmate, 46, was convicted of murdering Guy Gaddis in 1994
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Lawyers argues Tamayo was mentally impaired so ineligible for execution
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Court ruled that appeal was filed too late to prevent execution today
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High-profile case is a focus of protests in Mexico and diplomatic pressure
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Mexican government said it 'strongly opposed' the execution
'If you commit a despicable crime like this in @placeholder, you are subject to our state laws, including a fair trial by jury and the ultimate penalty.'