CHICAGO (CBS) — Traffic on Lake Shore Drive was disrupted again on Thursday, this time as police returned to the scene where a toddler was critically injured in a road rage shooting this week.

Meanwhile, a suspect has been arrested in the case, and Kayden Swann – the 21-month-old boy who was shot in the rolling road rage incident on Lake Shore Drive downtown on Tuesday – has had a medical upgrade.

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Police on Tuesday were in the field near the Museum Campus looking for more evidence after shots were fired during the road rage incident on Tuesday. One of the bullets struck Kayden.

Traffic was halted as police combed through the area where the Tuesday midday shooting took place. They still have not found the driver who shot and struck Kayden in the temple.

An arrest was made Thursday. Prosecutors said the man who was arrested was Kayden’s grandfather — who they say had a gun, but did raise it, fire it, or even indicate to the other driver that he had it.

Jushawn Brown, 43, first taken in for questioning Tuesday at Lurie Children’s hospital, where the boy was being treated. Brown owned the white Lincoln in which little Kayden was traveling, and Cook County prosecutors said Brown is his grandfather.

At a bond hearing, an assistant Cook County State’s Attorney said there is no evidence that Brown, of West Englewood, was the aggressor in the incident and no evidence of Brown firing his gun — despite earlier statements from police claiming he did.

Brown’s bond was set at $5,000 – he must post $500 to be released. The judge allowed him to be released, on the grounds that prosecutors said the other driver was the aggressor coming in at high rate of speed, the and other driver brandished a weapon toward Brown.

Brown did have a weapon, but held it in his lap, and there is no evidence that he brandished it or incited the other driver, prosecutors said. The other driver had no way of knowing Brown was even armed, and was acting aggressively on their own accord, prosecutors said.

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Brown did have the weapon on him at the hospital when he went to check on Kayden.

His next court date is on Wednesday, April 14.

On Thursday morning, Lurie Children’s Hospital said Kayden “is demonstrating some return in brain activity” while getting critical care treatment in the hospital’s Pediatric Intensive Care Unit.

“As of last night, we were successful in lifting some of the sedation medication Kayden required to protect his brain,” Dr. Marcelo Malakooti, associate chief medical officer and medical director, said. “We are pleased to see Kayden make some recovery as he is demonstrating some return in brain activity.”

Kayden reamins in critical condition.

The 21-month-old boy was a passenger in a car shot at over the course of two blocks on northbound Lake Shore Drive near Roosevelt Road along Grant Park.

The car was shot at over the course of two blocks on northbound Lake Shore Drive near Roosevelt Road. Police said shots flew along the Drive for two blocks between 9th and 11th streets.

A Good Samaritan drove the gravely injured toddler and family from the Drive to Northwestern Hospital in Streeterville, and he is credited for giving the little boy a fighting chance.

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