COOK COUNTY MEDICAL EXAMINER NOW SAYS THAT THEY HAVE IDENTIFIED THE FOUR VICTIMS, BUT ARE NOT RELEASING THEIR IDENTITIES PENDING NOTIFICATION OF KIN. >> WE ARE HEARING FROM THE FOREST PARK POLICE DEPARTMENT THAT THEY DO NOT BELIEVE THAT THE ATTACKS ARE. THEY DO BELIEVE THE ATTACKS ARE RANDOM AND THAT IT DOESN'T BELIEVE OR APPEAR TO BE THAT THE VICTIMS WERE ROBBED AT ANY TIME. IN THE MEANTIME, COMMUTERS THIS MORNING REMAINING ON EDGE FOLLOWING THOSE MURDERS , THE RUSH HOUR FELT ANYTHING BUT NORMAL FOR SUBURBAN COMMUTERS LIKE THIS MAN, HE SAYS HE'S ON EDGE AFTER FOUR PEOPLE ARE SHOT TO DEATH WHILE RIDING A FOREST PARK BOUND CTA BLUE LINE TRAIN. I DON'T FEEL TOO UNSAFE. >> I WOULD JUST SAY THAT THERE NEEDS TO BE A LITTLE BIT MORE ACTION TAKEN AND A LITTLE BIT MORE SECURITY MEASURES TAKEN. THERE WAS A VISIBLE SECURITY PRESENCE THIS MORNING AT THE STATION, JUST A DAY AFTER CTA WORKERS DISCOVERED THREE PEOPLE MURDERED IN ONE TRAIN CAR AND ANOTHER PERSON KILLED IN ANOTHER CAR. >> THE HORRIFIC SCENE UNFOLDED MONDAY MORNING AROUND 530, AFTER THE TRAIN PULLED INTO THE LAST STOP HERE THIS MORNING, CHICAGO MAYOR BRANDON JOHNSON RESPONDED TO THE VIOLENCE. >> IT'S A TRAGEDY. I MEAN, LOOK, THE GUNS IN THIS COUNTRY ARE OUT OF CONTROL AND THE ACCESS THAT PEOPLE HAVE TO GUNS, IT'S OUT OF CONTROL. AND IT'S VERY SICKENING. INVESTIGATORS SAY THE VICTIMS, ALL ADULTS, WERE SLEEPING ON THE TRAIN WHEN THEY WERE KILLED. >> POLICE SAY THIS MAY HAVE HAPPENED CLOSER TO THE HARLEM BLUE LINE. STOP. MOST SECURITY YOU HAVE FOR IF YOU NEED MORE SECURITY AND PEOPLE ON THE TRAIN BECAUSE IT AIN'T IT. >> DON'T BE NOBODY ON THE TRAIN. SO JUST ON THAT WITH RANDOM PEOPLE IN, ANYTHING CAN HAPPEN. >> INVESTIGATORS SAY THE SHOOTER WAS GONE BY THE TIME OFFICERS ARRIVED ON THE SCENE, BUT WAS ARRESTED ABOUT 90 MINUTES AFTER THE ATTACK, CARRYING A WEAPON. THEY WERE ABLE TO IDENTIFY THE SUSPECT USING THE TRANSIT SYSTEM'S SECURITY CAMERAS. THEY ADD THAT THE CTA'S NEW ZERO EYES 24 OVER SEVEN GUN DETECTION SYSTEM, WHICH HAS BEEN INSTALLED AT CERTAIN TRAIN PLATFORMS BUT NOT IN TRAIN CARS, WAS NOT USED AT THE FOREST PARK STATION AT THE TIME OF THE INCIDENT. LITTLE COMFORT TO ORLANDO LEE, WHO'S WORRIED ABOUT PEOPLE LIKE HER WHO RELY ON PUBLIC TRANSPORTATION. PEOPLE DO NOT FEEL SAFE OUT HERE AND THAT'S I MEAN, JUST IN COMMUNITIES, PERIOD. >> SO MY POINT IS THAT THEY NEED TO HAVE MORE PATROLS AND THEY NEED TO DO SOMETHING ABOUT THE VAGRANCY. >> NOW, INVESTIGATORS ALSO ADD THAT IT APPEARS AS A SUSPECT AT TIMES WOULD WEAR A FACE MASK WHILE ON THE TRAIN AND ON THE PLATFORM. AS FOR THE MOTIVE, AS I'VE ALREADY MENTIONED, IT IS RANDOM IS WHAT POLICE ARE SAYING AT THIS POINT, BUT UNCLEAR AS TO IF THESE INDIVIDUALS WERE SPECIFICALLY TARGETED AFTER THE DECISION WAS MADE TO OBVIOUSLY HARM SOMEONE. WE ARE ANTICIPATING THAT ONCE THOSE CHARGES ARE FILED, THEN FOREST PARK POLICE WILL HAVE A NEWS CONFERENCE TO TALK