Essex evaded being taken into custody by jumping a chain link fence and running across I-10, while setting off firecrackers as a diversion. Essex then ran into Gert Town, and broke into the Burkart building, a warehouse and manufacturing plant on the corner of Euphrosine and South Gayoso. Upon entering the building, an alarm alerted police to a break-in. A dog unit with Officers Edwin Hosli Sr. and Harold Blappert responded to the call, not realizing the connection of the break-in to the attack on central lockup. When Officer Hosli went to get his German Shepherd out of the back seat of the car, Essex shot him in the back. Essex then started shooting the car, shattering the windshield. Officer Blappert then crawled across the front seat to the radio and called for back-up. Officer Blappert then fired four shots at the spot where he saw muzzle flashes from Essex's rifle, then he pulled his partner's body onto the front seat of the car and waited for back-up. When the back-up arrived, they sent two dogs into the building to search for Essex, but Essex had escaped again. Officer Hosli would later die from his wounds on March 5, 1973.

At 10:15 a.m. on January 7, 1973, Essex shot grocer Joe Perniciaro with his .44 Magnum carbine and then carjacked Marvin Albert as he sat in his 1968 Chevrolet Chevelle outside his house on South White Street. Essex drove Albert's stolen vehicle to the Downtown Howard Johnson's Hotel at 330 Loyola Avenue, across the street from City Hall and the Louisiana Supreme Court building. After almost hitting a startled motorist in the hotel's parking garage, Essex began to climb the stairs, only to find the fire doors locked on floor after floor.

Gaining entry from a fire stairwell on the 18th floor, the top floor of the building, Essex told three startled black hotel employees not to worry, as he was only there to kill white people. In the hallway in front of room 1829, Essex found 27-year-old vacationing Dr. Robert Steagall and his wife Betty, a couple from Virginia enjoying a belated honeymoon. After a struggle with Steagall, Essex shot him in the chest and shot Betty in the back of the head. In the room, he soaked telephone books with lighter fluid and set them ablaze under the curtains. Essex dropped a Pan-African flag onto the floor beside the bodies of the couple as he left. On the 11th floor, Essex shot his way into several rooms and set more fires. On the 11th floor, he shot and killed Frank Schneider, the hotel's assistant manager, and shot Walter Collins, the hotel's general manager. Mr Collins died in the hospital three weeks later as a result of his gunshot wounds.

The police and fire department quickly arrived. Two officers tried to use a fire truck's ladder to enter the building, but were shot at by Essex. A few minutes later, Essex shot and killed NOPD Officers Phillip Coleman and Paul Persigo from his perch on the 18th floor.  Attempting to rescue trapped officers, Deputy Chief Louis Sirgo was fatally shot in the spine by Essex. Lt. Lewis Townsend, a Tulane medical student, walked into the open field to carry the wounded officer to safety, then returned to class.

Seeing the story on TV, Lt. General Chuck Pitman of the United States Marine Corps offered the use of a CH-46 military helicopter to assist the police officers. The helicopter was loaded with armed men and dispatched to the hotel. By this time, Essex had retreated up to the roof of the building where he and the helicopter exchanged many rounds over many hours. As nightfall came, Essex managed to hole himself up in a concrete cubicle that would protect him in the Southeast side of the roof. As he stepped out once again in the open to fire again on the helicopter, and after hitting the helicopter's transmission, Essex was barraged with fatal gunfire from police sharpshooters on the roofs of adjacent buildings as well as the automatic weapons aboard the helicopter. An autopsy later revealed more than 200 gunshot wounds.

New Orleans police later entered the residence of Essex at 2619½ Dryades Street and found the apartment completely covered from floor to ceiling with anti-white graffiti.  (From http://en.wikipedia.org/wiki/Mark_Essex)

After the Howard Johnson Mark Essex sniper incident, Joseph Rault reported that two well-dressed men, one fitting the description of Essex,entered the Rault Center on the morning of the fire (November 29, 1972).  A security guard spotted them, acting suspiciously, entering the ground-floor lobby  elevator after reading the building directory.  They were later seen in the lobby by the guard. (See also November 29)