Three young men were detained by police after the April 20 shooting at Columbine High School

RELATED VIDEO CNN has obtained an audio tape of Harris and Klebold from a court hearing they attended last year, and CNN's Tony Clark speaks to the judge about the boys (April 27) Real 28K 80K Windows Media 28K 80K To view the latest video streams on the Littleton school shooting, use the arrow buttons below to scroll through the video gallery.        Windows Media Real        28 K 80 K INTERACTIVE Amid grief, moments of reflection Audio and Images Interactive Map: Recent school shootings in the U.S.  ALSO: Columbine teachers prepare for students' return Parents of hospitalized Columbine students hope for best Big schools can mean isolation, opportunity Fatalities at Columbine High  MESSAGE BOARD: Listening After Littleton

April 28, 1999
Web posted at: 4:23 p.m. EDT (2023 GMT)

In this story: Discrepancies in story Sheriff: Gunmen tried to escape Marines rejected Harris RELATED STORIES, SITES

LITTLETON, Colorado (CNN) -- Three young men taken in for questioning after they showed up outside Columbine High School during last week's massacre have been cleared of any involvement in the school shooting, according to the Jefferson County Sheriff's's Department.

Earlier, Mark Paulter, Jefferson County's chief deputy district attorney, told CNN that surveillance videotapes from the school captured a "very chaotic" scene as Eric Harris, 18, and Dylan Klebold, 17, hurled homemade bombs and opened fire on terrified students in the cafeteria.

Nine students remained hospitalized Wednesday.

Authorities previously had not said whether the tapes contained any useful images. The tapes were sent to an FBI lab in Quantico, Virginia, for a frame-by-frame enhancement and analysis.

During a late night news conference on Tuesday, Jefferson County Sheriff John Stone said authorities found discrepancies in the information provided by three unarmed young men in dark jackets and combat-style boots who were frisked and taken off for interrogation after they were spotted in a field near the school.

He also said the three young men were able to name the gunmen before their names had been released. Stone said one of the trio had been expelled from Columbine High.

Investigators tested them for gun residue after the shootings and found no evidence that they had fired guns, Paulter said.

Jefferson County Sheriff's Department spokesman Steve Davis said Wednesday that the three men have been cleared of any involvement in the school shooting.

Stone said that Harris and Klebold initially tried to escape through three separate exits in the school, and killed themselves only after being turned back by police gunfire each time.

Investigators have questioned Klebold's 18-year-old girlfriend, who police say bought at least two weapons used by Klebold and Harris in the attack. Investigators want to know whether she knew how the guns were to be used. Authorities describe her as a witness, not a suspect.

Gary Sowell, 50, an employee at a hardware store in Littleton, told investigators he saw Harris and Klebold buy propane tanks, wire, screws, nails and duct tape -- material believed used in the bombs.

Stone said police gunfire prevented Harris and Klebold from fleeing the school through three separate exits

Meanwhile, Marine Corps officials said Harris had tried to enlist but was told during a home visit from a recruiter on April 15 -- five days before the massacre -- that he had been rejected for medical reasons.

The Marines refused to discuss the medical reason, but a Harris family friend, Victor Good, told The New York Times that the teen had been taking psychiatric medicine -- a potentially disqualifying factor -- and was seeing a psychiatrist.

A spokesman for the Marine Corps Recruiting Command in Virginia told CNN that any recruit under a doctor's care for virtually any reason would be disqualified for service.

Correspondent Tony Clark and Charles Zewe contributed to this report.