Chicago police are searching for a man who allegedly stabbed four homeless people, killing one in a recent series of attacks.

“According to police, four homeless men were stabbed with a knife in separate incidences by an unknown offender. One of the men died from their injuries,” ABC 7 reported.

In each case, the suspect approached the victims while they slept and stabbed them in the neck with his left hand, authorities explained.

The victim of the alleged homicide, 53-year-old Aaron Curry, was found dead at 1125 South Michigan in Grant Park on July 9 after someone noticed he had not moved for several days, CWBChicago reported.

The article continued:

He struck most recently aboard a Red Line train at the 95th/Dan Ryan station around 3:30 a.m. Tuesday, August 18, according to police. Investigators also revealed for the first time that the offender carried out another attack on the Red Line at 1:51 a.m. on July 15 at the 63rd Street station.

“Another homeless man was critically wounded at 3:51 a.m. on July 24 while he slept in virtually the same spot where Curry died, according to police,” the report said.

Investigators described the male suspect as slender, about 5’9″ to 6’1″ tall, wearing a sweatshirt with “Aero 1987” printed on the front.

As of Thursday morning, the condition of the three homeless victims was unknown, according to WGN9.

“Police are reminding the public to always be aware of your surroundings and pay special attention to people loitering in the area. They also say to never go after a suspect and try to walk in pairs when you can,” the ABC 7 article noted.

Anyone with information about the incidents was asked to call Area Three Detectives at (312) 744-8261.

The department also encouraged people to leave anonymous tips at home.chicagopolice.org.

In addition to the recent stabbings, more than 20 people, including a nine-year-old boy, were shot in Chicago on Wednesday, according to the Chicago Sun-Times.

“The nine-year-old boy was on a sidewalk with his mother ‘in the 300 block of North Central Avenue’ around 1:15 p.m. when gunmen got out of a vehicle and opened fire on them,” Breitbart News reported.

The child and his mother, both shot in the lower back, were transported to a local hospital and expected to survive.