New York (CNN) -- The unemployed apparel designer who killed a former coworker near the Empire State Building on Friday morning left his Manhattan apartment intending never to return, according to a police source with knowledge of the investigation.
The police source told CNN that when Jeffrey Johnson closed his door, he left the keys behind for the landlord before heading off to shoot Steven Ercolino.
The landlord was surprised, the source said, because Johnson was scheduled to move out a week later on August 31 in anticipation of apartment renovations. Johnson apparently told the superintendent earlier in the week he had found a new place to live, had placed his cats with friends and that, "Things would be resolved by Friday."
On that day, Johnson, 58, returned to Hazan Import Corp., the company where he'd been laid off about a year earlier due to downsizing.
Police say he waited outside for Ercolino, a 41-year-old sales executive whom he blamed for losing his job. He shot Ercolino five times in the head, according to the New York City medical examiner.
Police are searching through files on Johnson's computer found in his apartment, along with several books on shooting such as "Sniper: The Techniques and Equipment of the Deadly Marksman," according to the police source.
After the shooting, Johnson quickly walked to Fifth Avenue, trying to hide among large planters. A construction worker was among those who dashed after the gunman after the initial gunshots. He alerted counter-terrorism officers assigned to the Empire State Building.
They responded and ordered Johnson to freeze. Instead, he reached into his bag and pulled out his handgun. The police source said, "Was he trying to escape the police by shooting his way out? Or disregarding his orders? You can't get into his mind."
Two officers fired 16 rounds, hitting Johnson at least seven times.
Nine other people were injured -- two after being shot by police, seven from bullets that fragmented. The NYPD uses hollow-point bullets that prevent collateral damage by mushrooming once inside the body. However, a number of the bullets struck the large planters and fragmented -- causing seven of the nine bystander injuries.
Two of the wounded remain hospitalized -- a woman reported to be in good condition and a male in fair condition -- according to Evelyn Hernandez, director of media relations at NYC Health and Hospitals Corporation.
The two officers were praised by city officials for their quick response and their accuracy in taking down the gunman. As per NYPD procedure, they are on administrative duty -- with guns and badges -- pending the outcome of the investigation by police and the district attorney.
Johnson's elderly parents and a sister in Gainesville, Georgia, have not yet claimed his body.