"We don't take these allegations lightly nor will we," said Jersey City Police Chief, Thomas Comey.
Comey confirmed what Eyewitness News can report exclusively, Frederico Bruno came to this police precinct the day before his alleged deadly rampage, walked right up these stairs and into the lobby.
"Exactly 3 minutes and 12 seconds he goes down the stairs," adds Comey.
The question police have been trying to answer since Friday, what happened in the 3:12 minutes and Who did Bruno talk to if anyone, and should they have run his name.
A source tells Eyewitness News that Bruno identified himself and asked if he had any outstanding warrants. He was told by an officer behind the desk to go to the warrants squad.
Bruno did have outstanding warrants. If the officer had seen that and arrested him, would Friday's horrific attack have been prevented?
"Could it be in the realm of possibility? Anything can be in the realm of possibility... Is it in the realm of probability... I highly doubt it," adds Comey.
Cheif Comey say internal affairs will Get answers. Every officer working that day there is being interviewed.
"We have yet to come up with an officer who interacted with him in this precinct doesn't mean it didn't happen this is a fairly busy precinct," he adds.
24 hours later, police say Bruno hid in his girlfriend's apartment attacked her and her friend stabbing them both. He's then accused of throwing his ex and their 3-month-old boy out this window to the concrete three stories below.
Then they say he climbed down a fire escape and continued to beat his ex with a table. She is in a coma and the baby boy died.
Now the Jersey City police department is asking, Could they have prevented the attack before it happened?
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