SAN DIEGO -- Police released a new sketch Thursday of a man wanted in connection with a recent string of attacks on homeless people in the San Diego area that left three men dead and a fourth gravely injured.

The slew of brutal attacks occurred between July 3-6. San Diego police investigators believe they are all related.

The body of the first victim, 53-year-old Angelo De Nardo of San Diego, was found the morning of July 3 in an open area off the 2700 block of Morena Boulevard in Bay Park. An autopsy determined that De Nardo died prior to being set on fire.

Sixty-one-year-old Manuel Mason was found severely wounded in an area near Valley View Casino Center in the Midway district shortly before 5 a.m. on the Fourth of July.

Less than 90 minutes after the assault on Mason, 41-year-old Shawn Longley was found dead at a park on Bacon Street in Ocean Beach.

About 5 a.m. on July 6, 23-year-old Dionicio Derek Vahidy was gravely injured in the area of Broadway and State Street, and a towel he was sleeping under was doused with a flammable liquid and set ablaze, according to police. Vahidy died in a hospital Sunday afternoon.

Anthony Alexander Padgett, 36, was arrested on July 7 in connection with the attacks, but released Monday after SDPD officials said they did not have enough evidence to hold him.

Padgett was convicted of assault and mayhem for setting a sleeping man on fire in National City in 2010 and was sentenced to four years in prison. He blamed drugs for the attack and said he only intended to scare the victim.

Natalie Bartko has been deep into the manhunt since the first day. She works as a floral designer at Pistils and Petals in Bay Park.

"We came in 30 minutes after it happened so the whole day and the past couple of weeks have had an eerie feeling around it, absolutely," said Bartko.

She and co-workers have become very watchful.

"More alert, more cautious, more of our surroundings; checking out transients, whoever's walking by; high alert," Bartko added.

Teresa Clarks owns a neighboring pet grooming salon, Doggies Divine. She told 10News, "Still out there; absolutely it's very frightening; very alarming, especially for women, that there's somebody out there that could easily overtake us."