CHICAGO (CBS). — Four different people were held up at gunpoint on CTA ‘L’ trains and platforms in three separate incidents Thursday morning.

CBS 2’s Tara Molina has been tracking violence on our public transit – a subject about which the city will not talk.

The lack of comment from the city is not for lack of trying. We’ve been reaching the Chicago Police Department, the Chicago Transit Authority, and the Mayor’s office almost daily at this point about this uptick in crimes.

So we found someone else to weigh in.

Sitting on a Pink Line train near the Kedzie stop in Lawndale around 1:50 a.m., a 23-year-old woman was the first of four victims. Police initially said this robbery happened at 12:50 a.m., but later corrected their narrative.

Chicago Police said two men approached the woman, and “one of the offenders produced a handgun and put the gun on the side of her head while demanding all her personal property.”

A mere five minutes later on the same platform of the same station, the same thing unfolded. Two men – one of them 45 and the other between about the ages of 25 and 30 – said they had just gotten off the train when two men came up and robbed them at gunpoint.

Police will not say if the two robberies are connected.

A couple hours later, around 4 a.m., there was another gunpoint robbery on an ‘L’ train in a different part of the city. This time, a 48-year-old man reported he was asleep on a southbound Red Line train when a robber woke him up and robbed him at gunpoint.

This happened near the Bryn Mawr station in Edgewater neighborhood. The victim stayed on the train until the Clark/Division subway stop, where he reported the incident.

Thankfully, none of the four victims were injured.

The incidents Thursday morning have now been added to more than 10 we’ve been tracking since early last week, across Chicago.

CBS 2’s Molina asked specific questions about each incident – including the three incidents early Friday morning, as well as these others:

• An attack on a man at Belmont and Kimball avenues in Avondale on Tuesday just before midnight;

• The stabbing of a 40-year-old man on a Red Line train at the Chicago Avenue subway station in River North at 11:45 a.m. Tuesday;

• A shooting on a Route 53 Pulaski CTA bus in the 700 block of South Pulaski Road on Sunday, in which the shooter got away northbound on foot;

• A Pink Line attack on a woman near the Harold Washington Library-State/Van Buren stop downtown around 10:30 p.m. Saturday, in which a woman was assaulted. The assailant took of northbound on State Street;

• A stabbing around 6 p.m. this past Friday at the Roosevelt Red Line subway station, with a fight that started on the mezzanine and was followed by a fight in the street in which the assailants punched and kicked the man while he was on the ground. Five juveniles have been charged in that incident.

• A robbery in which a man was stabbed at 10 p.m. Wednesday, April 6, at the Cermak-McCormick Place stop on the Green Line;

• An incident just after 11 p.m. Tuesday, April 5, in which a man was punched by a group of people at the Lake Street subway station on the Red Line downtown;

• An attack on Monday, April 4, in which a train operator was pushed onto the tracks as he looked down for a cellphone someone said they dropped at the Granville Red Line station in Edgewater.

For the Roosevelt station attack this past Friday, police said they do not have any information beyond the charges when asked if there were any updates – or if the juveniles who were arrested are believed to be connected to other recent crimes.

For all the others, police responded, “Detectives are still investigating.”

The CTA and the Mayor’s office did not respond to requests for comment Thursday.

With little to no response from all of the city departments we’ve pushed for answers to questions about the spike – and the decision to add unarmed security guards to the CTA to target it – we brought questions to security expert Phil Andrew, who has decades of experience as a member of the FBI- Phil Andrew.

Andrew said simply, “The CTA is really just another area that is being policed less than it should.”

“It’s critical for the success and economics of the city that we’ve got to invest in more actual uniformed police on those CTA trains,” Andrew added.

There is also an advanced camera network rolling on the CTA system – we’ve seen it ourselves, and we’ve shown it to you. So why isn’t the city sharing those images – with so few arrests in the incidents we’ve tracked the past two weeks?

This is the answer police have provided repeatedly: “If detectives establish a pattern of crimes that are connected, they will create a Community Alert, which our office will disseminate at that time.”

But Andrew said, “The use of the technology needs to really be leveraged.”

He said independent of increasing uniformed police on the CTA – something he acknowledges is difficult given police staffing right now – the use of the surveillance camera system to aid in public safety could be helpful.

“Releasing images and repeating that we’ve got a safety issue is really challenging, but we’re never going to get through that without using the cameras effectively,” Andrew said. “It really is a bit of a Catch 22. If you’re not going to use the information you have effectively, to engage the public in enforcing and solving and trying to repress that criminal activity, you’re not going to engage them back to ridership.”