A New Jersey auto mechanic fatally mowed down an elementary school teacher and sped off — to the body shop where he worked, quietly patching up his Jeep before he was nabbed, authorities said Wednesday.

Following a night of drinking to celebrate his 39th birthday, Ibn Collins allegedly ran down second-grade teacher Meghan Crilly as she and three friends were crossing a Linden intersection around 2 a.m. Jan. 20, but he “did not slow down or stop,” officials said.

Instead, he headed back to his own auto body shop in Westfield — about seven miles from the scene — where he hid his red Grand Cherokee from prying eyes, ordered replacement parts and repaired it piecemeal in the two months since the crash, authorities allege.

Among the parts in need of repair was the Jeep’s battered bumper, which Collins scrapped — but detectives tracked to a salvage yard in Pennsauken, NJ, about 70 miles from the scene of the crash, officials said.

Collins was nabbed without incident at his Linden home Tuesday evening, and hit with charges including manslaughter and evidence tampering.

Officials said that convictions on charges of that nature are “commonly punishable” by up to 30 years behind bars.

He’s due in court Monday.

Crilly, 35, was initially left in a coma in a Newark hospital, before succumbing 11 days later to her injuries, which included spinal damage, several shattered bones and a lacerated liver, according to a GoFundMe drive raising money for Crilly and her family.

“While this arrest doesn’t bring her back, we believe it is a first step toward securing the justice Meghan and her loved ones deserve,” said Union County Prosecutor Michael Monahan.