VIDEO: Man charged in Manhattan killing spree pictured before chilling attacks

The chilling moments before a deranged man went on an unprovoked fatal stabbing spree across Manhattan Monday were captured on video, footage obtained by the Daily News shows.Ramon Rivera, 51, is seen on surveillance video changing clothes and removing a knife from his bag moments before he attacked his first victim (Obtained by Daily News)
A disheveled Ramon Rivera, 51, is seen on surveillance video just moments before he attacked his first victim, 36-year-old construction worker Angel Lata Landi around 8:20 a.m. on W. 19th St. near Tenth Ave. in Chelsea.
In the video, Rivera is seen standing next to a parked car, taking a sweatshirt out of a backpack and putting it over his stained t-shirt and trousers before donning a tan trench coat and beanie hat.
Rivera then chillingly pulls two large knives out of the backpack and puts them in his sweatshirt pocket, the video shows.
Minutes later Rivera walked up to Lata Landi, who was working at a nearby construction site, and stabbed him in the abdomen “without warning,” NYPD Chief of Detectives Joseph Kenny said Monday, describing the unhinged attack.
Medics rushed Lata Landi to Bellevue Hospital, where he died at 8:30 a.m., police said.
After attacking Lata Landi, Rivera ran off in search of his second victim. Around 10:27 a.m., Rivera stabbed a 68-year-old man who was fishing in the East River Promenade near the Water Club at E. 30th St. and FDR Drive in Kips Bay. Less than a half-hour later, at 10:55 a.m. Rivera attacked a 36-year-old woman at E. 42nd St. and First Ave. in Murray Hill.
The names of the second and third victims were not immediately released pending family notification, cops said. Medics rushed both to Bellevue Hospital, where the man was pronounced deceased. The woman died just before 6 p.m., according to a police source.
According to police, a passing cab driver saw the last assault, mistook it for a robbery, and flagged down a nearby cop.
 NYPD Officer Robert Garvey, who was posted near the United Nations, caught up with Rivera and took him into police custody.
Rivera is charged with multiple counts of murder. While in custody, he confessed to committing all three killings, a police source told The Daily News.