Two men killed in a pair of brazen Rogers Park shootings over a 36-hour period were shot in the head at close range with bullets that came from the same gun — and likely the same shooter, police said Tuesday.

Calling for help from the public, Chicago police released a surveillance video of a person in a mask wanted for questioning in the two murders — one of a 73-year-old man walking his dogs on Sunday morning, the other of a 24-year-old man of the Orthodox Jewish faith slain on a lakefront path late Monday.

“This person is clearly trying to disguise themselves,” Chicago Police Supt. Eddie Johnson said at a Tuesday press conference at the 24th District police station. “Clearly he or she knows what they are going out to do.”

The elderly victim, Douglass Watts, was walking his dogs just after 10 a.m. Sunday near his home in the 1400 block of West Sherwin when someone walked up and shot him in the head, according to police and the Cook County medical examiner’s office.

A day and a half later — and about a half-mile down Sheridan Road — Eliyahu Moscowitz was walking on the Loyola Park bike path about 10:20 p.m. Monday near Lunt Avenue when someone shot him in the head behind his ear, authorities said.

Johnson said the investigation is “still in the preliminary stages,” but expedited ballistic tests performed by the ATF confirmed that the shell casings found at the scenes of both shootings came from the same gun.

A motive is unknown.

Police initially said Watts might have been shot during a robbery, but Johnson said Tuesday that nothing was taken from either victim. There is no evidence the men knew each other or that the offender had specifically targeted either of them, police said.

‘Senseless and tragic’

Johnson did not rule out the possibility the shootings were hate crimes.

“It’s just too early to be able to say that definitively, though we are looking at every possibility,” he said.

Mayor Rahm Emanuel urged neighborhood residents to “go about your daily lives, but be safe, smart and vigilant at the same time.

“Two men, different ages and backgrounds whose lives ended with the same gun used. Their deaths were senseless and tragic,” Emanuel said.

The surveillance image released by police Tuesday came from near the scene of Watts’ killing, showing a person dressed in all-dark clothing with a hooded mask. Police describe him as a black male with a thin build.

“There is someone out there who knows who this person is, whether it’s a family member, a friend, a trusted loved one — we need you to do the right thing and call the police,” Johnson said.

Watts’ shooter took off west on Sherwin and then southbound in the west alley, police said.

Moscowitz: ‘He was a shining star’

Detectives were still reviewing security video and identifying possible witnesses in Moscowitz’s death.

The 24-year-old worked for more than two years as a mashgiach at Jewel-Osco, supervising the preparation of kosher foods.

“Our hearts go out to the family of Eliyahu Moscowitz,” Jewel-Osco spokeswoman Mary Frances Trucco said in an email. “Eliyahu was also very personable and well-liked by his colleagues.”

About a hundred of Moscowitz’s friends, many from the city’s Pokémon Go scene that the 24-year-old was active in, gathered for a vigil Tuesday night steps away from the lakefront path where he was killed.

Friends remembered an avid traveler and bicyclist who had recently returned from a trip to Australia — and who would turn down the offer of a ride in favor of his bike, rain or shine.

“He died doing what he loved: exploring Rogers Park,” said Marco Ayillo, recalling how he met Moscowitz a few years back.

“He jumped off his bike with this big smile and I thought, ‘Here is someone I want to know. … He was as kind as he was sarcastic, and as funny as he was smart,” Ayillo said.

“You make friends playing games. You don’t think you’re going to lose someone,” fellow Pokémon gamer Steve Loskutov said. “He was a shining star in every single way.”

Nathan Smolinski said Moscowitz had joined the 900-member Pokémon Go group Rogers Park Raid about a year ago and quickly became a fixture in the community.

“We’re telling our members not to play late at night and to travel in groups,” Smolinski said. “But we’re not going to be scared out of playing. … This game brings people together.”

Chicago police spokesman Anthony Guglielmi confirmed Moscowitz was likely playing the popular game at the time of his death.

Watts: ‘The sweetest, kindest, gentlest man’

Watts had lived in Rogers Park with his husband, Brian for five years, according to a post on an online fundraising page set up to pay for Watts’ funeral expenses after the “shocking act of violence” that took Watts’ life. The page had raised more than $6,400 as of Tuesday night. The couple met in 2007, had a civil union in 2011 and married in 2015, the post said.

Police were adding extra patrols to Rogers Park in the aftermath of the connected killings.

Two marked police cruisers and at least one additional unmarked vehicle made passes within a 45-minute span on Tuesday evening down Sherwin Avenue, where flowers, candles and a note from a neighbor vowing that “those of us here will not let your death be in vain” marked the sidewalk outside Watts’ apartment complex where he was gunned down in broad daylight.

News of the related killings added to the tension on the block.

“I’m pretty rattled by it, and so are a lot of my neighbors,” said Fallon Sowers, who lives in a building adjacent to Watts and would stop to chat with him as he was out walking his black pug and tan mixed-breed.

“He was the sweetest, kindest, gentlest man,” Sowers said, adding that she’s working with Ald. Joe Moore’s (49th) office to organize a block club to bolster a sense of community safety.

One neighbor — who declined to give her name out of fear in the wake of the murders — said Watts and his husband took the dogs out daily and called Watts “the most devoted dog-dad.”

“If you’re not safe walking your dogs around here on a Sunday morning, when are you safe?” the neighbor said. “It’s terrifying to think that this killer is out there.”

Victims’ advocates canvassed the block, passing out flyers with the police community alert and a photo of the suspect.

G. David Drury stopped to view the memorial for Watts as he walked his own shih tzu mix Nelson down Sherwin Tuesday evening. Drury said he was walking to work about two blocks away on Sunday morning at the time of Watts’ killing.

“Everyone around this neighborhood looks out for one another,” he said. “I hate feeling that I can’t trust a person walking down the street.”

Prior to the murders of Moscowitz and Watts, the Rogers Park neighborhood had recorded two murders and 14 nonfatal shootings in 2018, according to CPD data. Last year, four people were killed and another 11 wounded by gunfire in the North Side neighborhood.

Ald. Moore said police would hold a meeting at 7 p.m. Wednesday at the Loyola Park field house, 1230 W. Greenleaf Ave., to update residents on the investigation.

Anyone with information is asked to call detectives at (312) 744-8261, or dial 911. Tips can be left anonymously at cpdtip.com.