MADRID—Spanish Tourism Minister Reyes Maroto said on Monday she had received a knife covered in red stains in the mail, and police announced they had identified a suspect. El Pais newspaper, La Sexta television, and other media reported that the main suspect was a man with mental health issues and that police were not linking the incident to a recent series of death threats to other public figures. Reuters could not confirm those reports independently. Politicians across the political spectrum initially raised the alarm when Maroto said she received the package. The knife had arrived on Friday with a return address on the package, she said. The National Police said they had identified a person believed to have sent the knife and the investigation was ongoing. Investigators did not believe the suspect had any link to death threats mailed last week to Interior Minister Fernando Grande-Marlaska, Pablo Iglesias of Unidas …