
Nicholas Glenn, 25, identified as the gunman who injured two Philadelphia police officers and killed woman, 25, during Friday ambush

A gunman was shot dead in Philadelphia after he ambushed and shot two cops and four civilians, killing one of the bystanders, in a 'targeted attack on police'.

Nicholas Glenn, 25, has been identified as the lone gunman, according to Philadelphia Police Commissioner Richard Ross.

One 25-year-old woman was killed in the attack and two officers were hospitalized.

Three civilians were also wounded, including one who remains in critical condition.

A note believed to be written Glenn that allegedly contained rambling anti-police rhetoric and named a specific parole officer as a target was recovered near the scene.

Ross said Glenn first ambushed Sgt Sylvia Young, 46, late Friday night just a few blocks from the University of Pennsylvania campus.

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Sgt. Sylvia Young, 46, with the Philadelphia police was injured along with officer Ed Miller

A picture from the scene on Friday night when two police officers were shot in Philadelphia

Bullet holes can be seen in Young's police vehicle following the rampage, where she was shot up to eight times directly in her protective vest

Young said Glenn didn't say a word when he began to fire into her marked police cruiser around 11.19pm.

The 19-year veteran was trapped in her vehicle when Glenn fired 18 times at close range with a 9mm Ruger, Ross said at a press conference on Saturday.

Young was struck multiple times in her left arm and protective vest as she leaned into the passenger side to shield herself.

Ross said Dunn also struck Young's service weapon twice, disabling the weapon.

'I don't even know if she would've been able to return fire if she had to,' he said.

She was shot up to eight times directly into her vest, according to sources.

Nearby officers saw that Young had been shot and began to chase Glenn, according to the Philadelphia Inquirer.

As he fled Glenn fired five rounds into a bar called the Maximum Level Lounge on 51st and Sansom, wounding a security guard.

He then grabbed a woman and 'used her as a shield' before shooting her in the leg, according to Ross.

Glenn ran two blocks before he fired 14 shots into a random white vehicle.

Young said Glenn didn't say a word when he began to fire into her marked police cruiser around 11.19pm on Friday night

Young, a 19-year veteran on the force (pictured left), was trapped in her vehicle and was struck in her left arm and protective vest

A 25-year-old woman was killed after she was shot seven times in the torso. Pictured the scene of the shooting

The 25-year-old woman inside was killed after she was shot seven times in the torso, according to CNN.

Ross said police are not yet releasing her name because it has not been confirmed that all her family has been notified.

A man who was also inside the car is currently in critical condition and is expected to survive, Ross said.

Glenn was then confronted by University of Pennsylvania police officer Ed Miller and two Philadelphia officers.

They opened fire and killed Glenn, Ross said.

Miller, a former sergeant who served for 33 years with the Philadelphia Police Department before retiring, was shot in the hand during the ambush.

Glenn has a number of drug-possession convictions in Philadelphia and was also charged in connection with a gang rape case in November 2009, court records show.

The rape case was withdrawn by prosecutors in December 2011 for reasons that are currently unknown.

'Right now we have a lot of questions,' Ross said on Saturday. 'This is completely a bizarre situation.'

Ross said that some of Dunn's letter found at the scene alluded to issues he had with a probation officer and 'not being particularly fond of the police department', but revealed most of it focused on himself.

'A lot of talk in the first person about himself and what he does and doesn’t do, and issues he has with a whole bunch of other things,' Ross said.

The envelope was entitled 'Doomed'.

'I guess he was referring to anyone who was going to be in his path last night,' Ross said.

Glenn was shot dead after he was confronted by Miller and two Philadelphia police officers

Mayor Jim Kenney praised the officers and pleaded with police to follow Young's example and wear their protective vests

Ross added that there is no indication that Dunn had been radicalized or that he has 'ties to anything else'.

Other than the rantings in the letter, there has also been scarce indication of what Dunn was motivated by.

Ross said he believes it will be 'very difficult' to learn much from the rambling letter, as it was more about Dunn himself than anyone he wanted to harm.

'Clearly there were some issues going on there,' Ross said.

The commissioner also confirmed that Dunn had a 'significant criminal past' and was 'well-known to the police department'.

Authorities do not yet know how the convict was able to obtain a weapon, as the gun's serial number had been obliterated.

Ross said Young and the security guard, both of whom he visited at the hospital, are in 'good spirits'.

The commissioner also praised the Philadelphia officers who followed Dunn on foot.

'The restraint they used...is nothing short of miraculous,' he said.

'This guy is firing at everybody on the street that he sees but there’s so many people out there that they probably elected not to discharge their weapons for fear of hitting innocent civilians’

Ross added that Dunn had 'carried out one of the most violent acts' seen in Philadelphia for some time, and said he was 'absolutely astounded' by the fact Young had survived.

Philadelphia police officers are currently patrolling in pairs following the incident.

Mayor Jim Kenney praised the officers and pleaded with police to follow Young's example and wear their protective vests.

'Thank you for what you do for us every day, and please, please, please, every shift, please wear your vest,' he said. 'They will save your life, as we saw tonight.'