Riley County Police Department Director Brad Schoen, left, holds a press conference with Interim Lawrence Police Chief Anthony Brixius, right, Thursday, July 27, 2017, in Manhattan.

Manhattan ? A suspected serial rapist linked to attacks on 13 university students in Lawrence and Manhattan from 2000 to 2008 appears to have resurfaced more recently.

Law enforcement officials from both Kansas college towns announced Thursday that a new attack reported in 2015 shares characteristics of the previous 13 — sparking renewed focus on the case and a plea for information from the public to help solve it.

Police said after a “lengthy investigation” into the 2015 report, they concluded the assailant is likely the same man that attacked women in the previous cases. Authorities did not give details about the decision to advertise the link now, but Thursday’s news conference was scheduled on the two-year anniversary of that crime.

Police said there may be yet-unreported attacks by the same man, and warned University of Kansas and Kansas State University students to be watchful for the risk of future attacks.

“We need the public’s help,” Lawrence police interim Chief Anthony Brixius said.

“We believe it is possible a similar incident or an attempt has occurred but was not previously reported to law enforcement or was not linked to these cases for any number of reasons. It is also likely that a member of our community or someone outside of these two communities has witnessed something or has a piece of information that could help us bring this suspect to justice.”

Authorities historically have publicly shared little about the case.

On Thursday, they shared some previously unreleased details, but said much was still being withheld to protect the integrity of the investigation and any eventual prosecution.

Law enforcement authorities created a website, kansascollegerapist.com, with information about the case and how to share tips with police.

The website urges: “Help catch a rapist that has terrorized our communities.”

“While the physical violence of the assaults was usually limited to the rape itself, these were all violent acts carried out by an assailant who did so in a cold, calm, calculated manner,” Riley County Police Department Director Brad Schoen said.

There are a total of 14 attacks — 12 rapes and two attempted rapes — with enough similarities for police to suspect the same man, Schoen said.

The first 13 occurred between Oct. 1, 2000, and Dec. 1, 2008, in Manhattan and Lawrence, according to a list of specific dates and locations of attacks released, for the first time, on Thursday. The last known attack linked to the suspected serial rapist was reported July 27, 2015, in Manhattan.

Nine of the attacks occurred in Manhattan and five in Lawrence, with all the Lawrence crimes reported between 2004 and 2008, according to the list.

Though none of the rapes and attempted rapes occurred on campus proper, all the victims were KU or K-State students, Schoen said.

Here’s what authorities know about the rapist’s appearance and methods, Schoen said:

• In each incident, a masked intruder entered the victim’s home — mostly between about 2 and 4:30 a.m., as she slept. Homes varied from apartment complexes to duplexes to single dwellings.

• In most cases, the assailant threatened the victim with a handgun. Schoen declined to answer the nature of statements, if any, the assailant made, citing the ongoing investigation.

• Police frequently were able to identify where the assailant entered the home, but the way he got in was not always known. Many victims said they locked their doors, yet there were no signs of forced entry.

• There are indications that victims had been surveilled by the assailant prior to the attack.

“We assume that because, for example, the victims are home alone, and they’re awakened. They’re asleep when he enters the apartment,” Schoen said. “That indicates some period of observation beforehand.”

• All but one incident happened during a break in college classes.

Victims typically described the assailant as a white male between 5 feet 9 inches and 6 feet tall, with various estimates of build, weight and age, Schoen said. Based on incident dates, police think the assailant is at least 35 years old now.

He said one other physical characteristic featured prominently in most of the victims’ descriptions of their attacker: He was heavy-set, specifically with a “prominent stomach.”

Schoen did not answer whether DNA evidence had been collected or tested, citing the ongoing investigation.

Included in the renewed push to solve the serial rapes is an anonymous donation of $10,000 to the Riley County Police Department, to use as reward money for information leading to an arrest in the case.

Local law enforcement re-issued an updated alert to other agencies nationwide in case any have similar, unsolved cases, Schoen said.

Lawrence and Manhattan police have updated the Kansas Attorney General’s Office and Kansas Bureau of Investigation on the case status and contacted the KU and K-State administrations, Schoen said. Police have worked with the KBI, FBI and U.S. Marshal’s Service during the course of the investigation — for evidence collection and evaluation, offender behavioral analysis and investigative recommendations — and continue to work through leads.

Prior to Thursday’s news conference, police contacted each victim and shared the information that would be released, Schoen said. He said authorities reiterated their commitment to investigate each case to “the fullest extent possible, employing any and every means of police and forensic science.”

Authorities urged anyone with possible tips to contact police. That includes people who may have seen or had an encounter with someone matching the description around areas where crimes were reported, even if it was years ago.

“Major cases are frequently solved with information provided by citizens,” Schoen said, “thus we need your help to hasten the assailant’s identification and prevent additional assaults.”