A blood-covered lunatic toting two knives trekked across Manhattan in a savage broad-daylight stabbing spree that left two men dead and a woman clinging to life Monday, cops said.

The sick suspected stabber – a mentally ill homeless man with eight past arrests in New York City alone – was stopped by a hero cop thanks to the help of good Samaritans, including a cab driver and a British tourist, said NYPD Chief of Detectives Joe Kenny and police sources.

Ramon Rivera, 51, was identified by sources as the person of interest in custody, seen with a long beard and unwieldy hair in a grizzled mugshot obtained by The Post. Police have no other suspect in the spate of “unprovoked” random attacks, said Mayor Eric Adams during a morning briefing.

“Today, we have three innocent New Yorkers, just going about their lives, who were the victim of a terrible, terrible assault,” he said. “It is a clear, clear example of the criminal justice system, mental health system that continues to fail New Yorkers.”