A female-led carjacking gang led police officers on a dangerous chase that ended with them trapped, shot - and an unborn baby dead.

The incident happened on June 20 when officers attempted to stop a stolen Chevy SUV after it was wanted in connection with two armed robberies earlier that day.

After the car fled, officers gave chase and filmed as it weaved in and out of traffic, clipping at least two other cars and almost causing crashes.

The vehicle then entered a construction lane on a freeway and collided with a cement truck.

When the driver of the vehicle reversed into a squad car officers opened fire, hitting Ashley Patterson, 18, and killing her unborn child.

Prosecutors have since charged Patterson alongside her boyfriend Calveyon Jeans, 17, Semira Dean,18, Tyrone Rogers, 17, and two other youths with a combined total of 20 crimes.

One of the male teens was left in a serious condition, while Patterson suffered life-threatening injuries. She has now been released from hospital.

According to a complaint seen by WISN, Dean is said to have been to the ringleader of the group who called themselves the 'Crash Out Dummies'.

Prosecutors say they would rob people and steal vehicles in downtown Milwaukee, with Dean having stole the car earlier in the day.

The complaint says that Dean also made off with '$200 and some marijuana' from a drug dealers, admitting to cops she stole vehicles for expecting buyers.

The teenager told officers she had stolen four cars the day before, with the group having attempted to steal one rental car earlier on June 20.

The complaint said that one woman was approached by three teenagers who demanded her keys and grabbed at her, before she managed to fight them off.

Less than 30 minutes later another person was approached by two teens while sitting in his vehicle.

Prosecutors say a young female knocked on his window and asked about restaurants before a young male pulled a gun on him.

The two demanded the man out of the car before they drove away in the vehicle. Prosecutors say Dean, Jeans, Patterson and Rogers watched from another car.

After officers managed to stop the gang, they found a county sheriff's deputy firearm inside the vehicle.

The gun was linked with a stolen vehicle belonging to a Waukesha County sheriff's deputy in September of last year. He had left his badge and weapon inside the car.

Police recovered the vehicle in January, but the duty weapon was missing from it. Jeans admitted to officers that he, Dean and another stole the gun last year.

Investigators say the gun was used in numerous other carjackings before it was recovered from the crash site.

Calvin Jeans, the father of Calveyon, told reporters his son had a history of run ins with the law, and that he had exhausted all way to try and get his own son help.

The youth has prior convictions of driving a vehicle without consent, with all teens charged have 'extensive records' involving stolen vehicles.

Police had released the body cam footage after pressure from families of the alleged and activist group Milwaukee Alliance Against Racist and Political Repression.

The 25-year-old officer who fired shots was placed on administrative duty, per department policy.