Officers said that after speeding away, Cassamajor wrecked the car a few blocks away, leaving the toddler in the snow.
Family members were already rushing to the crash scene and ultimately helped police make the arrest by holding Cassamajor down until officers arrived.
“As soon as we came down the street right here, he jumped out and we started chasing,” one family member said.
The Department of Social Services has been notified due to the fact that the child had been left in the car unattended.
“You don’t ever expect that to happen, but of course, you jump into to action mode because you think, ‘What if that was my child?’” a family member said.
Cassamajor is expected to face a judge on Monday.
The boy was not hurt, police said.