Authorities are requesting public assistance in the search for a man who is believed to have abducted and sexually assaulted at least a dozen women and teenage girls in the South Los Angeles area in the past four years.

The latest crime occurred Dec. 15 , and the earliest crime occurred in January of 2014, Los Angeles police Capt. William Hayes said at a news conference at LAPD headquarters.

“The suspect approaches females that are involved in prostitution activity, has a conversation with them, gets them in (his) vehicle, and then at gunpoint takes them to a remote area of the county near South Los Angeles, where he sexually assaults them, and then releases them,” Hayes said.

The victims range in age from 15 to 46 years old, Hayes said. No serious injuries have been reported.

The abductions have occurred in the Alameda Corridor area, Hayes said.

The corridor is a 20-mile-long rail cargo expressway linking the ports of Long Beach and Los Angeles to the rail network near downtown Los Angeles, according to the Alameda Corridor Transportation Authority.

Hayes declined to be more specific on the locations of the abductions or the locations where the sexual assaults occurred, citing the ongoing investigation.

The suspect is described as Black, between 5 feet 8 inches to 6 feet 1 inch tall, weighing about 180-220 pounds, and about 30-50 years of age. He was bald, and had a “salt-and-pepper” goatee or beard.

He drove a couple of different vehicles: an older-model black pickup truck with tinted windows; and a white four-door sedan, possibly a Toyota or Nissan. No license plate information was available.

Hayes said the man was linked by investigators to three cases via DNA evidence, and to the other cases based on his method of operation and other undisclosed reasons.

The LAPD investigation began with a sexual assault in May of this year in the LAPD 77th Street Station’s jurisdiction in South Los Angeles, Hayes said.

DNA evidence was obtained from that victim that led investigators to a DNA match in a sexual assault case in sheriff’s jurisdiction in January of 2014.

A third case also was linked via DNA to the same suspect, Hayes said.

Investigators compared those cases and others, and developed a pattern to the crimes, Hayes said.

“Not only do we want to warn the individuals that are involved in the prostitution activity, we also want to see what information we can solicit that would identify the suspect,’’ Hayes said.

Any other possible victims, or anyone with information on the case, was urged to call detectives Dara Brown or Daniel Aguirre of the Robbery- Homicide Division at (213) 486-6910, or (877) LAPD-247.