District Attorney Kevin Steele said several co-workers witnessed the attack on Angela Stith (pictured), 33, on Friday

A man stabbed and then repeatedly drove over his estranged girlfriend, crushing her in a fatal attack as her suburban Philadelphia co-workers tried to help her early Friday morning, authorities said.

The attack was captured on surveillance cameras.

District Attorney Kevin Steele choked up as he described the man driving over the woman 'again and again and again' in a security firm parking lot.

He said the suspect, Lawrence Crawley, set himself on fire after being pulled over by a Pennsylvania State Trooper several hours later on the other side of the state. Crawley, 33, was hospitalized in critical condition.

Steele said several co-workers witnessed the attack on Angela Stith, 33, and tried to help her.

'This was a terrible death. And I know and I feel for the victim and what she went through, her family and what they went through, the people who witnessed this and the people who are going to witness this moving forward,' Steele said.

Scene of the crime: Stith was allegedly hit by her estranged boyfriend's car 'again and again and again' at the Vector Security parking lot (pictured)

Before the alleged attack, Stith was seen on camera leaving her office about 2:15am and heading to her car while texting someone

Authorities said Stith, who worked at Vector Security, was seen on camera leaving her office about 2:15am and heading to her car while texting someone.

Steele said she had talked to and had texted the suspect recently.

Stith got into her car, and the suspect is seen in the footage smashing her driver's side window in an effort to attack her.

Authorities said the attack began when the suspect smashed the driver's side window of Stith's car and began stabbing her outside the Vector Security parking lot

She fled out of the passenger side of her car and ran a short distance before the suspect caught her, beat her and stabbed her repeatedly.

Co-workers came out to try to help Stith, calling 911. Steele said she can be heard answering their questions

Meanwhile, Steele said Crawley got into his Chevy Suburban and drove over Stith, circling the parking lot and driving over her two more times as her co-workers watched, helpless to stop him.

Steele said Crawley turned the three-ton vehicle 'into a weapon' before fleeing.

The arrest affidavit said there was a relationship history between Stith and Crawley. The affidavit said Crawley pleaded guilty to simple assault after a May incident in which he choked Stith.

A medical examiner said Stith died Friday from a combination of sharp force trauma and blunt trauma.

Officials said Crawley stabbed her so hard that a knife blade was still wedged into her back when the autopsy was performed.

As he fled, Crawley called his mother and another woman to tell them he had killed Stith and that he was sorry.

District Attorney Kevin Steele (pictured) said when authorities pulled over suspect Lawrence Crawley on Friday, he lit himself on fire inside of the cab of his car

Steele said when the trooper was able to finally pull Crawley over, he lighted himself on fire inside of the cab of his car.

The trooper was able to save him and he was taken to the hospital, where he was in critical but stable condition as of Friday afternoon.

Steele said he planned to charge Crawley with first-degree murder and other charges and would ask to deny bail.

It was unclear from records whether Crawley had an attorney. A phone call to a number listed for him went unanswered Friday.

Whitemarsh Police Chief Christopher Ward said his staff pleaded with him not to watch the video because they knew he would have to speak to reporters Friday.

He said there hasn't been a murder in the township of about 17,000 people in 17 years.