The back-to-back killings in Rogers Park seemed to be as random as they were brutal: an elderly man walking his dogs just steps from his home on Sunday and then, barely 36 hours later, a young man walking blocks away on the Lakefront Trail near Loyola Park. Both were shot once in the head, left for dead.

But police on Tuesday confirmed what for many residents was their worst fear: The same gun was used to shoot both men, most likely by the same gunman. Just about every other detail remains a mystery.

What is clear is that the killings of Douglass Watts, 73, and Eliyahu Moscowitz, 24, have shaken the neighborhood known for its diversity, prompting Mayor Rahm Emanuel to urge residents to use caution as they go about their daily lives.

“To all the residents of the Rogers Park community, your city is standing with you, supporting you, at this moment,” Emanuel said at a news conference. "I know firsthand the Rogers Park community is strong, is resilient and is a supportive community. We need those core values and the Police Department needs those core values at this time.”

Chicago police said Watts and Moscowitz did not appear to know each other. Police have not found a motive behind the attacks. Nothing was taken from the victims during the shootings.

Chicago Police Department Chicago police released an image of the suspect in the fatal shooting of a 73-year-old man in Rogers Park on Sept. 30, 2018. Police have determined the same gun was used in the killing of a 24-year-old man, just blocks away, on the lakefront path by Loyola Park on Oct. 1. Chicago police released an image of the suspect in the fatal shooting of a 73-year-old man in Rogers Park on Sept. 30, 2018. Police have determined the same gun was used in the killing of a 24-year-old man, just blocks away, on the lakefront path by Loyola Park on Oct. 1. (Chicago Police Department)

“Given the frequency of these homicides and what we know about the investigations, detectives have been working aggressively to cultivate leads," police Superintendent Eddie Johnson said.

Asked whether police were investigating the shootings as a possible hate crime because Watts was gay and Moscowitz an observant Jew, Johnson said it was too early to rule anything out.

A surveillance video of the suspect in the first attack showed a man wearing black pants and a black jacket with a hat and scarf pulled over most of his face.

As news spread about the shootings, residents of Rogers Park organized vigils, community events and even the start of a new block club.

Reading on Facebook that some residents were too scared to walk by themselves to the grocery store, Maciej Radzik offered to drive people there in his car.

Radzik, who has lived in the neighborhood since 2011, said he is frightened by the recent violence but is trying not to let it get to him.

“These are places that I walk by, I walk through,” Radzik, 45, said. “You’re trying to enjoy the neighborhood and make it better and you read about stuff like this.”

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In other attempts to create safety in numbers, some Rogers Park residents are organizing groups to walk dogs together.

To help residents feel safe, police will be increasing patrols, saturating the lakefront and surrounding areas in Rogers Park with officers, including those on bicycle patrol.

Loyola campus police also issued an alert to students and faculty warning “the offender in these murder investigations is an ongoing threat to the campus area,” even though the attacks did not happen within the school’s boundaries.

While some residents lamented that neighborhood safety has gotten worse in recent years, Grace Hussar, 34, said she continues to feel safe in her neighborhood and encouraged people to remain out and about despite the recent violence.

She organized an event Tuesday at Loyola Park for neighbors to come together, meet one another and talk about the shootings.

“When you walk around the neighborhood over the last couple of days, everyone seems on edge. No one is lingering,” she said. “There’s like this air of panic because nobody knows who did it.”

READ MORE: 'What could anybody possibly have against him?' Masked gunman kills elderly man walking his dogs in Rogers Park »

At the gathering, residents passed out flyers depicting a shooting suspect as Chicago police officers walked through the park.

Long considered one of Chicago’s most diverse neighborhoods, Rogers Park is a popular destination for new immigrants from Africa, central Asia, the Middle East and other parts of the world. It's also home to Loyola University Chicago.

The neighborhood is far from Chicago's most violent communities, though the Rogers Park police district — which covers the community itself as well as neighboring West Rogers Park and a part of Edgewater — has seen a slight jump in homicides over the last year.

Through September, and not counting Moscowitz’s slaying, the district had seven homicides compared to five last year, according to official Police Department statistics. Through the same time period, shooting incidents also jumped to 26 from 18, the department said. But shooting incidents in the district were still down by double digits when compared to the same periods in 2015, 2014 and 2013, the statistics show.

Aggravated battery crimes, however, have increased by 32 percent this year in the district, up from 68 to 90, according to the statistics through September.

Angela Kallies photo; Facebook Eliyahu Moscowitz, 24, left, was found shot in the head near Loyola Park on Oct. 1, 2018. Douglass Watts, 73, right, was shot in the head and killed Sunday morning, Sept. 30 in the 1400 block of West Sherwin Avenue in Rogers Park. Eliyahu Moscowitz, 24, left, was found shot in the head near Loyola Park on Oct. 1, 2018. Douglass Watts, 73, right, was shot in the head and killed Sunday morning, Sept. 30 in the 1400 block of West Sherwin Avenue in Rogers Park. (Angela Kallies photo; Facebook)

Typically, much of the violence in Rogers Park stems from protracted gang feuds that erupt, many of them occurring within several blocks of the CTA Red Line station at Howard Street and along blocks that surround the Red Line stop at Morse Avenue.

Both men, though, were shot in the eastern part of the neighborhood. Watts was killed in the 1400 block of West Sherwin Avenue, and Moscowitz was slain south of Loyola Park on the 1100 block of West Lunt Avenue.

On Sept. 2, a doctoral student at Northwestern University was killed by apparent stray gunfire in the neighborhood while walking toward the Howard “L” station. Shane Colombo, 25, was fatally struck by gunfire near Howard and Clark streets — about a mile and a half from where Moscowitz was found dead Monday night — when two men began shooting each other.

Almost exactly a year ago, 64-year-old Cynthia Trevillion, a teacher at Waldorf School in Rogers Park, was shot and killed Oct. 13 while walking with her husband to the Morse “L” station. Police have said that she was not the intended target of that shooting.

Ald. Joe Moore, 49th, who lives about a block and a half from where Watts was killed, said he could see why people are on edge.

“Obviously people are very concerned, understandably, and frightened,” Moore said. “This is not something that is a common everyday occurrence in our neighborhood.”

At Tuesday’s news conference, Emanuel expressed condolences to the victims, though he hadn’t been able to reach both families.

Moscowitz, who supervised a kosher kitchen at a Jewel-Osco store, was fatally shot on the evening of Simchat Torah, a Jewish holiday that celebrates reading the final chapter of the Torah before restarting the scroll. His family would not use technology during the holiday, so Emanuel said it wasn’t appropriate to call them yet.